HVAC Mode Actuator door replacement [Archive] - Page 2 - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

: HVAC Mode Actuator door replacement


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salto jorge
11-13-2009, 12:17 AM
An alignment issue kept gears from meashing correctly.

To align the unit, the pin in the HVAC gear must sit in the notch in the mode control actuator gear.

One way to correct the alignment issue........

Manually position the vents so that they are open all the way (Turn the HVAC gear, all the way clockwise).

Looking at the front of the actuator unit, side facing outward there are two long marks and two short ones. (Metal insert up).

Position the actuator gear so that notch in the steel section that you can see is between the smaller left and large center mark.

To move the arm
Pull fuse 36, and replaced it.
Then turn the ignition switch on and off until the arm is in the correct place (using the marks).
The lower edge of the actuator arm (gear) will be slightly lower then the molded landing on the HVAC side of the actuator.
Be careful, the arm (gear) will slam into the end points on the new actuator unit and can damage it.

(No camera, No picture)

Install the new actuator
Using your hand manually turn the HVAC gear until the pin fits into the notch in the actuator.
Tighten it up
Pull fuse 36 again and replace it
Turn on the ignition
Let the unit center itself, 90 seconds more or less
Try the controls

Mine worked.

I recommend PLAYING around with the damaged unit being replaced and test fit it to make sure that it works for you.


One opportunity completed on the Envoy another awaits.

dlew133
11-15-2009, 07:28 PM
Thanks to Roadie for suggesting I replace the blower motor resistor. Did it this weekend - took about 20 minutes - and the settings work fine.

steve_kc
11-16-2009, 12:39 AM
It makes it hard to post questions cause every time i have one I find a post already... I just wanted to say thanks, my heater quit working today and I now know what I will be doing tomorrow when I get off work :)

Trailblazerfans
11-23-2009, 01:05 AM
It makes it hard to post questions cause every time i have one I find a post already... I just wanted to say thanks, my heater quit working today and I now know what I will be doing tomorrow when I get off work :)

Thats because this is such a great site with alot of information. Good luck with the repair it should be really easy.

clayton05envoy
12-12-2009, 05:12 AM
Thanks so much for all your help! I've been reading several different postings on this for the past week. I bought the new part, I'm just worried it's not the right one. I'm going out now to get ready to put it on...I'll post later & let you know how it turned out!:worried:

filthyfingers
12-14-2009, 08:13 AM
Many posters are having trouble mounting the new module. I had the same problem.

WHY: The shaft that turns the module doesn't match the rotator position of the new module.

The FIX: Match the position of the new unit to the old one you just removed. Do that by hooking up the new unit electrically only. Adjust the mode control knob on the front panel. The new unit's rotator position will slowly spin. When it looks just like the position of the old unit, the new one will now mount up fine.

You might be done but go through the fuse reset process anyway.

clayton05envoy
12-14-2009, 06:54 PM
Unfortunately the part that was shipped to me was the wrong one. after a few minutes of screaming & throwing stuff, i realized they sent me the part for my rear ac/heater vents, which were broke as well...so i got that one changed instead.

all in all i don't feel it was an unproductive day, considering i figured out how to get to the front mode actuator, i should have it changed out in no time once the correct one comes in!

thanks for the tip on the new one when i get it in...i'm sure that we be the hang up that i have that will cause me to curse for about an hour!

jkoti2000
12-19-2009, 12:58 PM
I see two actuators. Which is which? and what are the Part Numbers for Both? at GMPARTSDIRECT.COM

89018675 ?
89018539 ?

nitz369
12-20-2009, 11:54 PM
So my 2002 Envoy obviously has the mode actuator issue. I have the dual climate control. Forever when you turn the ignition all it clicks, kind of loud, now it does that AND if you turn it to lower vents it makes a quieter click down lower.

My question:
Since I could care less about lower vents at this point, is there anyway to just pull the plug on the mode actuator? or fuse?

What would the clicking from the upper area be coming from?

Since this is 2002 I am not messing with trying to replace. just wondering if I can get the noise to stop.

gmcman
12-26-2009, 01:00 AM
If you want the noise to stop, you can unplug the actuator or replace it. I have to replace mine and after looking under the dash it's a piece of cake....just get the part and replace it.

I have warm A/C on the driver's side because of it...it's one of those things that everything will be better when you replace it.

Less than $40 and a little labor.....just do it, you will thank yourself. :thumbsup:

andrema
01-01-2010, 04:08 PM
Just changed my mode door actuator on a 2002 TB. I bought it from ACDirect on amazon.com for only $28. Shipping was slow but it was cheap! I used the modified anchor shackle to remove the cam from the actuator. Getting it off the cam with this method was easy!! Here are pics of the tool and the actuator. I opened up the old one and found that I only lost one single tooth off of one of the gears. It seems like you could probably find the gears somewhere and just replace the broken part. But for only 28 bucks...maybe best to just replace the whole unit.

Also, The tool was easy to make...5/16" anchor shackle and an 8 mm bolt. If for whatever reason you don't want to make one yourself, write me and I will mail mine to you. All I ask is that you return it when your done.

twins
01-12-2010, 09:47 PM
Hi! guys,can someone help me to change my hvac door acuator of my 2004 envoy slt,if you have some pictures of how to do it,because i need the heater on the dash and floor vent because i'm here in winterpeg or winnipeg,canada.
I hope someone can help me.thanks::confused:

the roadie
01-12-2010, 10:00 PM
Did you read the entire thread?

bprovie
01-14-2010, 12:26 PM
I have the same problem that the defroster and floor vents work, but the dash vents don't. There's a lot of mention about a clicking noise. Is that from gears of the actuator?
I do not have that noise. If I listen when I switch through the mode controls, I hear what sounds like a motor operating when I switch from defrost to floor vent. When I switch from floor to floor+dash, I hear the motor running for a much shorter time. When I switch from floor+dash to dash, I don't hear the motor at all. Could this still be the same mode actuator problem?

the roadie
01-14-2010, 12:47 PM
Probably. Start pulling panels to observe the actuator, and watch it move. Or not move, as the case may be.

We speculate the clicking is caused by broken teeth on one of the gears, after the motor overpowers the strength of the gear material while being calibrated, or the calibration is flawed, and drives the actuator shaft too far, and the airflow door jams against its stops, and then the gear teeth jump each other and start stripping out.

I constantly ask for people to send me their failed actuators for analysis so we can get a better idea what's REALLY happening, and so far only ONE member sent me one. Sigh....

bprovie
01-14-2010, 07:55 PM
I watched the gears. I see that only the defrost actuator is functioning. The mode actuator does not turn.

I took the actuator off. The gears do not look worn.

With the actuator off, the dash vents are on (regardless of the mode selection), and the floor vents trickle air (regardless of the mode).

the roadie
01-14-2010, 08:07 PM
Then it's almost certainly dead. Under $50 to change out. Just read the rest of this thread you're in.

KNBlazer
01-14-2010, 08:29 PM
ordered my mode actuator today from amazon, and it already shipped.. already have a tracking number... WORKS FOR ME... :hail:


$38.63

trumptmn
01-15-2010, 10:50 PM
Thanks to this thread, I was able to diagnose and fix this problem. My defrost vents were the only vents working, I was afraid I'd have to do the whole control unit. Just finished changing my actuator, works great. Thanks to everyone for the help! Now my wife will quit hassling me about her cold feet in the card!

KNBlazer
01-15-2010, 10:52 PM
ordered my mode actuator today from amazon, and it already shipped.. already have a tracking number... WORKS FOR ME... :hail:


$38.63


Ok very nice... part is being shipped from Minnesota... I guess Los Angeles was out ... otherwise it would have been installed already... :sadcry::raspberry

twins
01-16-2010, 02:35 PM
Purchased part number 89018675.

It took a few attempts to correctly install and align the part.
Once installed, I noticed that the arm on the actuator does not contact the sprocket on the HVAC system.

I have now disconnected the battery but have not pulled the fuse. (Disconnected for 10 mins)

If everything is correct based on what I have read, the control module begin the calibration process so that the gears mesh for the system to function.

The system does not function. The arm on the actuator moves but does not engage the sprocket on the HVAC side.

I can manually move the sproket on the HVAC side and control the air flow with the actuator aligned and attached to the unit. It is possable to make the gears mesh for one pass, but then they seperate when at one extreme and the contact/meshing of the gears is lost.


Is this a common issue ? What went wrong ?

I pulled the fuse in the box under the drivers side rear seat and it did not make any difference.






Hi! can you tell me the things that you did to replace the actuator because i having a problem to take it out,i tahe off the lower dash in the bottom of the steering wheel but i can get through to get the actuator,or may be if you have some pictures,thanks

the roadie
01-16-2010, 04:08 PM
Hi! can you tell me the things that you did to replace the actuator because i having a problem to take it out,i tahe off the lower dash in the bottom of the steering wheel but i can get through to get the actuator,or may be if you have some pictures,thanksHave you read the entire thread? How about post #1 that had some pictures? And instructions?

bprovie
01-16-2010, 04:51 PM
Thanks for the help, Roadie. One more thing--

I was going to bench test it before I got the new part. The schematic I saw showed that the brown was from the fuse and the tan went to the mode door control on the control module. Does the module complete the circuit to ground through the tan wire?

I know I probably do need the new actuator, I just wanted to check it first.

the roadie
01-16-2010, 05:15 PM
The schematic I saw showed that the brown was from the fuse and the tan went to the mode door control on the control module. Does the module complete the circuit to ground through the tan wire?Difficult to bench test with only clip leads, unless you also have an adjustable voltage source or a pot you can hook up as one.

Brown is +12

Yellow is ground

Tan/black is the control signal, and will control the actuator CW or CCW depending on if it's high, low, or stop motion if it's midpoint/open/high impedance. I forget which direction it goes for either phase of the control signal

Light blue/black is the 5V reference for the position feedback sensor pot

Light green is the pot wiper for position feedback

And given that the problem with most failed actuators is that the calibration process slams them into the mechanical stops and gear teeth break, or the teeth skip and then the feedback pot doesn't agree with where the gears are expected to be, a bench functional test isn't likely to tell you much. Most of them still run the motors, it's just that the control module algorithms get to their endpoints and die, and the calibration solution doesn't converge, or else the pot (that has no mechanical stops) wraps around, and the algorithm can't handle the sawtooth waveform - it's expecting a straight ramp from CW to CCW stops.

andrema
01-16-2010, 09:37 PM
Here is a picture of what I found when I opened the actuator up. Like I said in the previous post, 1 tooth on one of the gears.

85vette
01-17-2010, 10:12 AM
Question: Why couldn't they spend another 3 bucks and use brass gears?

Answer: They probably anticipated the breakage and manufactured another 30K of these 8 dollar, made in China, Mexico, or _______ (fill in the blank)actuators so they could sell them to us for $70+ a pop....

bprovie
01-26-2010, 11:59 PM
I have the new actuator and I've read the posts about installing it, but I just want to be sure of a couple things before I install it. I'm also an electrician, not a mechanic, so here's what I have to say in lamens terms.

When looking at the exterior side of the actuator (where you see the silver part of the gear), there are notches on the silver part of the gear and 3 marks on the black plastic. The notch is almost aligned with the center mark (it's a bit to the left of it). Is that bi-level (floor+dash) ?

When I try to operate the HVAC on the vehicle, the mode only cycles between defrost and floor+dash.


Do I need to do anything before installing it?

lonewolf1986
01-31-2010, 12:02 AM
thanks for all the info, i just replaced mine today, took apart the old one none of the teeth were broke so i put a 9V battery to the motor and nothing happened

tmr1
02-05-2010, 08:22 AM
I just replaced my mode actuator due to the dash vents not working; it wasn't too bad of a job; you just need to be patient and smart as you work.

First you need to find out what part number to order; just call the local GM dealer. you will need to give them your VIN; the P/N I used was 89018675 and I got it from www.parts4chevys.com for $46.33 which was alot cheaper than the dealership.

Remove lower dash covers. The actuator is located behind the middle portion of the dash; if you lay on the floor and look to the left you will see it.

Remove gray air duct as shown in pc #53; just pull it from it's endpoint; this way you can get to the actuator better.

There's 2 actuators; you want the one with the white gear coming out the side; it's the lower one in pic #52. You will need a 5.5mm socket to get the 2 screws out; be careful not to drop the screws; take your time.

Pic #46 shows the actuator; the two horizontal holes are where the screws mount; the other one close to the wire connection has a dowel that helps locate the actuator. You will need to adjust the white gear shown in pic #46
to be at the same location as the gear on the actuator you removed in order for it to go back in correctly. There are 3 marks on the back of the plastic housing (as seen in pic #46) and also slots in the metal part of the gear drive, the top slot is in the 1'oclock position in pic #46. Be sure your new actuator gear position matches the old and it will drop right in. I put the screws in the socket and then wrapped electrical tape around them so the screw wouldn't fall out during assembly. The whole thing took me 45 minutes.
The vents now work like a charm and I saved a bunch of coin!

You can doooo eeeet!

I have the same problem after replacing the battery and I manually moved the mode damper to blow out the dash vents until I can get the part and replace it since we are in Florida and would rather for now have the AC blow out the dash vents

This is great info and I have two questions
I read on another post that a special tool was needed to pull the actuator from the vent shaft.
1. Did you have this tool or did it come off with out it?
2. When replacing the actuator did it go back on the shaft easily or did it need to be pressed on some how?

Thanks in advance for your help

jimmyjam
02-15-2010, 09:20 AM
I read on another post that a special tool was needed to pull the actuator from the vent shaft.
1. Did you have this tool or did it come off with out it?
2. When replacing the actuator did it go back on the shaft easily or did it need to be pressed on some how?
I believe you need a tool to remove the mode door, not the actuator. I replaced mine yesterday and all you really need is small hands which i don't have. and yeah, it just pops back in there as long as the shaft is aligned like the one you removed.

And don't look at the old one that failed, if you are like me you'll be disgusted by the poor design. I think roadie had the same issue as me, the external plastic gear wasn't pushed in far enough and eventually the little micro-splines gave way. I mean sure, they could use a screw to hold it together, or just put a notch in the metal part or bigger splines but then I'd miss out on the fun contorting my body to replace it... :duh:

I am going to throw some glue on the shaft of the old one and keep it handy for NEXT TIME :sadcry:

the roadie
02-15-2010, 10:07 AM
I believe you need a tool to remove the mode door, not the actuator. Getting the mode door out of the plenum requires pretty much total removal of the dash. As the saying goes, when they build a car - they start with the heater core and then everything else is attached to that. :dielaugh: So don't ever break the tip of the shaft off the mode door.

The screw tool is sometimes, but not always, required to pull the actuator off the door shaft.

KNBlazer
02-15-2010, 10:48 AM
from what I've read, only early model TV's require this tool to remove the mode actuator... I didn't need it...

bprovie
02-16-2010, 10:39 PM
I replaced my actuator a couple weeks ago, and everything seems good. One different issue I had was that my old actuator was not in one of the typical 3 positions it should've been, so I wasn't sure what position to put the new one in. My new actuator was in the middle position (probably bi-level), so I adjusted the gear on the mode door to be roughly in the middle of its travel. So far everythings good. Thanks Roadie.

RedEnvoyDenali
02-16-2010, 10:48 PM
I just replaced my mode actuator due to the dash vents not working; it wasn't too bad of a job; you just need to be patient and smart as you work.

First you need to find out what part number to order; just call the local GM dealer. you will need to give them your VIN; the P/N I used was 89018675 and I got it from www.parts4chevys.com for $46.33 which was alot cheaper than the dealership.

Remove lower dash covers. The actuator is located behind the middle portion of the dash; if you lay on the floor and look to the left you will see it.

Remove gray air duct as shown in pc #53; just pull it from it's endpoint; this way you can get to the actuator better.

There's 2 actuators; you want the one with the white gear coming out the side; it's the lower one in pic #52. You will need a 5.5mm socket to get the 2 screws out; be careful not to drop the screws; take your time.

Pic #46 shows the actuator; the two horizontal holes are where the screws mount; the other one close to the wire connection has a dowel that helps locate the actuator. You will need to adjust the white gear shown in pic #46
to be at the same location as the gear on the actuator you removed in order for it to go back in correctly. There are 3 marks on the back of the plastic housing (as seen in pic #46) and also slots in the metal part of the gear drive, the top slot is in the 1'oclock position in pic #46. Be sure your new actuator gear position matches the old and it will drop right in. I put the screws in the socket and then wrapped electrical tape around them so the screw wouldn't fall out during assembly. The whole thing took me 45 minutes.
The vents now work like a charm and I saved a bunch of coin!

You can doooo eeeet!

And for this my Dealer told me minimum 8 hours at straight time. Looks like the USA doesn't have a monopoly on shoddy dealers.

Ascender2004DAR
02-18-2010, 05:57 PM
First time poster. Thanks for sharing all of your knowledge and experiences.

I have an '04 Ascender, which has mostly the same components as the Trailblazer and Envoy. I experienced the same problem with no air flow thru the dash vents; only floor and defrost airflow (surprisingly enough, this occurred after the battery was disconnected to rectify a performance issue). The mode actuator seems to be spring loaded, and with the actuator actually removed, the default position of the affected baffle is thru the dash vents.

The perfect tool to get at these awkwardly located mounting screws is the Craftsman Offset Ratchet Screwdriver/Bit Wrench and a 7/32" socket with 1/4" drive. The Offset Ratchet has a thumb wheel which allows you to work with one hand.

While running the various tests suggested on this forum, I noticed something that no one mentioned. Maybe this is an Izusu issue. With both of the air-flow actuators disconnected, when I moved the mode selector between dash, dash/floor and floor positions, I could hear another actuator. But I couldn't determine where it was located. Based on all of the posts here, there are only four such actuators, the other two being the temperature actuators (dual controls). It didn't sound like these were the affected actuators. Any ideas?

the roadie
02-18-2010, 06:15 PM
While running the various tests suggested on this forum, I noticed something that no one mentioned. Maybe this is an Izusu issue. With both of the air-flow actuators disconnected, when I moved the mode selector between dash, dash/floor and floor positions, I could hear another actuator. But I couldn't determine where it was located. Based on all of the posts here, there are only four such actuators, the other two being the temperature actuators (dual controls). It didn't sound like these were the affected actuators. Any ideas?Thanks for the hint about the great tool. I don't believe Isuzu is different, but which two actuators did you disconnect? There are really five. If you left the recirculate one connected, I'm guessing you're hearing that one change state. If you change the mode to defrost, recirculate is over-ridden to let outside air enter. Recirculate is only available in dash and bi-level modes, so there's the possible cross-connection.

******************************************

Ascender2004DAR
02-19-2010, 08:04 AM
By the way, I also found the replacement part at AC-Direct (via Amazon.com) for $38.02, delivered.

ABenvoy
02-24-2010, 02:52 PM
Hi all. Like many others I find myself joining because I have a technical issue with my 2002 Envoy.

My problem has been mentioned in a couple other posts, but they didn't list what solved the problem.

I have heat only on the drivers side, in all modes, but on the passenger side I have cold air blowing. The cold air force on the passenger side is a lot stronger then the heated air on the drivers side.

I originally took it to a dealer for diagnoses. The diagnosed it as the passenger actuator and quoted me $1200 to do the job, because of the dash removal. I then searched this forum and decided to do the change myself.

I changed the passenger actuator and did the reset, but nothing has changed.

When I do the reset and when I change the different modes I can hear all the drivers side actuators working. When I do the reset the passenger side moves CW then all the way to the end CCW then stops. That is the same position the old actuator was in when I replaced it.

Is the control module gone. Is the actual door broken. Any other suggestions?

Update. After a couple more resets, I can now see the passenger actuator rotate when I change the temp settings, but the problem still exsists.

KNBlazer
02-24-2010, 10:52 PM
the only thing I can think of is that you didn't adjust it properly prior to installation... I am not familiar with your model year actuator as there was a design change somewhere in the 02-03 model..RoooooooooooooooooooooOOOOOOOOOOOOOADEEEEEE EEEEEE, we need assistance... lol.. :crackup:



Hi all. Like many others I find myself joining because I have a technical issue with my 2002 Envoy.

My problem has been mentioned in a couple other posts, but they didn't list what solved the problem.

I have heat only on the drivers side, in all modes, but on the passenger side I have cold air blowing. The cold air force on the passenger side is a lot stronger then the heated air on the drivers side.

I originally took it to a dealer for diagnoses. The diagnosed it as the passenger actuator and quoted me $1200 to do the job, because of the dash removal. I then searched this forum and decided to do the change myself.

I changed the passenger actuator and did the reset, but nothing has changed.

When I do the reset and when I change the different modes I can hear all the drivers side actuators working. When I do the reset the passenger side moves CW then all the way to the end CCW then stops. That is the same position the old actuator was in when I replaced it.

Is the control module gone. Is the actual door broken. Any other suggestions?

Update. After a couple more resets, I can now see the passenger actuator rotate when I change the temp settings, but the problem still exsists.

ABenvoy
02-25-2010, 09:08 AM
Thanks for the response.

Not sure what would need adjusting. I can see the actuator rotate through it's full cycle when I adjust the passenger temp setting.

KNBlazer
02-25-2010, 09:30 AM
Thanks for the response.

Not sure what would need adjusting. I can see the actuator rotate through it's full cycle when I adjust the passenger temp setting.

but do you see the actual door rotate? if the 02 is anything like the 04 "ACTUATOR MODE DOOR" then this might also have a notch on the door where you have to line up the actuator to this notch...

when I did the mode actuator on my 04 TB, I had to pull the darn thing out 3 times, 4th time was a charm... in order to adjust it properly to the notch that the actuator itself has, is by pulling the fuse and then putting it back in and allowing the actuator while looking at it to go through its cycle and shutting power off when it reaches that notch...

Dewaholic
03-27-2010, 04:13 PM
I just got done pulling mine out to inspect it. I pulled out the white part and it had hash marks on the actuator so I just marked it when I pulled it out. Now, the white part had very fine teeth and a few were worn down a bit, but I noticed as it turned, any amount of pressure and it would jump.

So, I ended up taking the cover off the actuator to look at the insides and there are 3 or 4 other gears inside with good size teeth. The one thing I did notice was that the big gear had broken 2 teeth, the smallest was broke in half and a third had a few teeth missing from all over. Needless to say, this unit is junk. I will post the pics of the inside if anyone wants.

03 Envoy JRL
03-27-2010, 05:04 PM
The passenger actuator is facing a steel welded brace just left of the glove box area. Has anyone replaced this, without removing the entire dash assembly? I still think that all the actuators (that I can see) are fine because they move quietly and smoothly, without clicking. Is that a safe assumption?

I just ordered a temp control module on ebay. Hope thats it.

I'm gonna take a break from all this Envoy stress and do my taxes :crazy:

I have not read past this yet but I am in the same boat. Can not remove the passanger side actuator so I have given up because I reallllly do not want to remove the dash..03/31/10 she goes to my local mechanic to fix I am SOL because I wanna save the $$$$$$$$ but i AM LOOSIN MY CENTS trying to fix this...well :thx

03 Envoy JRL
03-27-2010, 05:24 PM
I just got done pulling mine out to inspect it. I pulled out the white part and it had hash marks on the actuator so I just marked it when I pulled it out. Now, the white part had very fine teeth and a few were worn down a bit, but I noticed as it turned, any amount of pressure and it would jump.

So, I ended up taking the cover off the actuator to look at the insides and there are 3 or 4 other gears inside with good size teeth. The one thing I did notice was that the big gear had broken 2 teeth, the smallest was broke in half and a third had a few teeth missing from all over. Needless to say, this unit is junk. I will post the pics of the inside if anyone wants.

:woot:Please post those pics I am dropin my 05 off 03/31/10 to local mecahnic because I have had enough but if his price is High I will do it myself (BTW This site I great I am hooked reading other stuf not only my problems):thumbsup:

daveyboy43
04-01-2010, 06:17 PM
Guys,
I have an 03 Trailblazer with dual climate control. Yesterday I noticed a clicking or tapping noise coming from the drivers side dash when I first started the car and when I switch on the defroster. The noise goes away when I switch on the dash vents or lower heater vents so I'm assuming I have an actuator problem Just want to be sure which one needs replaced and where it's located. Also when I switched the controls to off so nothing was working the noise stated again. All suggestions and advice greatly appreciated.

the roadie
04-02-2010, 01:20 AM
Check post #286 for a picture of actuator locations.

daveyboy43
04-02-2010, 06:38 AM
So based on the noise coming from the top of the dash safe to assume it's the window defroster actuator. Is it fairly easy to gain access to that one and why is it making the tapping sound when I turn it off?

mounder4830
04-03-2010, 09:13 AM
Hey guys great site! Heres my dilema. I have a 2003 TB with the upper vents that blow in all modes. I have pulled the #36 fuse to recalibrate to no success.

Here is what happens in each mode:
Vent= Vent
Floor + Vent = Floor + Vent
Floor + Defrost = Floor + Defrost + Vent
Defrost = Defrost + Vent

Soooo...if its the actuator thats bad...which one is it?

the roadie
04-03-2010, 01:09 PM
Your problem is the airflow mode actuator.

******************************************

daveyboy43
04-03-2010, 01:15 PM
Hey roadie can I get your comments on post #297. Just want to be sure before I order the part and get this started.

the roadie
04-03-2010, 02:07 PM
The tapping noise might be a failed calibration and the sound of gear teeth skipping across each other. Sorry, I've never changed that particular one, so I can't say if it's hard or easy. But then, I consider this kind of job medium difficulty.

http://www.roadie.org/dash03.jpg

daveyboy43
04-03-2010, 02:25 PM
Can I gain access to it by removing just the bottom panels or do I have to remove everything just like in your picture? Also today it's not making any noises. Does it possibly just need recalibrated and if so what's the easiest way just pull a fuse or something?

the roadie
04-03-2010, 02:35 PM
My project was for a grab handle. You should never need to go that deeply for just an actuator. And everybody should try a recalibration first by pulling the fuse, etc. Maybe two or three times before spending money on an actuator.

daveyboy43
04-03-2010, 03:25 PM
What fuse do I need to pull and is there anything else I need to do as far as recalibration goes?

the roadie
04-03-2010, 03:35 PM
Please http://forums.offroadtb.com/images/smilies/read.gif

2001FZ1
04-05-2010, 08:57 AM
Are all the actuators the same part number? I need the part number for the drivers side temperature actuator for my Rainier. Thanks!

Dewaholic
04-05-2010, 09:25 AM
The pics of my Mode Door Act.

the roadie
04-05-2010, 10:18 AM
Are all the actuators the same part number? I need the part number for the drivers side temperature actuator for my Rainier. Thanks!No, the GM designers weren't that clever. They didn't value the benefit that identical part numbers would have for owners in the later years, and the lower cost in the supply chain to have larger volumes of fewer part numbers.

I don't have it right at hand, but you can always find part numbers by drilling down at www.compnine.com - a fantastic resource for DIY mechanics.

Dewaholic
04-05-2010, 11:22 AM
For the actuator that changes for the floor to vents.

For 2004 Envoy (based on last 8 of vin)
Part # : 89018675

Local Dealer wants $102.85
Rockauto.com wants $41.79

just for you guys who were needing it.

Dewaholic
04-05-2010, 11:24 AM
Can I gain access to it by removing just the bottom panels or do I have to remove everything just like in your picture? Also today it's not making any noises. Does it possibly just need recalibrated and if so what's the easiest way just pull a fuse or something?


Just remove the panels underneath the driver side, once laying down looking underneath you will see 3 of the to your left. It will be the middle one. I tried the recal thing and it didnt work, so I pulled it to inspect it and you can see my pics.

2001FZ1
04-05-2010, 05:10 PM
No, the GM designers weren't that clever. They didn't value the benefit that identical part numbers would have for owners in the later years, and the lower cost in the supply chain to have larger volumes of fewer part numbers.

I don't have it right at hand, but you can always find part numbers by drilling down at www.compnine.com - a fantastic resource for DIY mechanics.

Is there any other problem that it could logically be other than a bad temp actuator? - passenger side is cooler than driver's side when the A/C is on.
I don't want to drop over $100 plus the effort if its not the problem. I just spend over $100 this last weekend replacing a wheel hub.

daveyboy43
04-05-2010, 05:17 PM
Tried recalibrating with no luck. Nothing from the dash vents but what's strange is the popping noise happens for about 30 seconds when I start the vehicle even though the controls are off. Any thoughts?

daveyboy43
04-07-2010, 10:03 AM
I know I'm experiencing some type of actuator problem but not sure what's going on. I'm not getting anything through the dash vents but why am I getting the tapping noise for about a minute when I start the vehicle even though all the controls are turned off.

the roadie
04-07-2010, 10:32 AM
Popping noises could be the actuator gears skipping/stripping as the calibrator attempts to go to a zero position. Sort of like the instrument needles moving around and then settling on zero if you pull their fuse or reseat the connector.

daveyboy43
04-07-2010, 10:42 AM
Should I attempt recalibration or is it shot at this point? Also is recalibration beast done with key in on postion or with engine running. Also even though I turn off the hvac controls, they are sometimes back on when I turn key on after recalibration. Should I turn it off or just leave it alone.

the roadie
04-07-2010, 10:50 AM
Some members report success after 2-3 recalibrations, but it's a crap-shoot. Personally, I pull the fuse for 30 seconds, reinsert it, don't touch any control and it doesn't matter if they are on or off, then turn the ignition to run without starting the engine. Just so I can observe the recalibration process for 90 seconds or so. I don't think it matters if the engine's running - it's just important to not touch any control.

If you're curious what's happening, just pull the dash access panels and look at the actuator shafts turning while they recalibrate. Removing the fuse more than once will be required to watch them all, but each recalibration process has its own risk of breaking additional actuators. That's why changing the battery kills a few of them and we keep reading fresh reports of actuator death.

TB_n00b
04-08-2010, 05:53 PM
That's why changing the battery kills a few of them and we keep reading fresh reports of actuator death.

This explains why my front vents are not working. SOB. Another expense on this f'ing car. Musta happened from disconnecting the battery last Friday when cleaning my TB.

I have no flow from the front vents, always flow from the defrost/floor regardless of settings even on defog only.

daveyboy43
04-10-2010, 03:50 PM
Just got done installing the new actuator. Just want to know is there anything special that needs to be done prior to turning the ignition on and when I do turn it on do I need to have the heater controls set on anything or turned off?

the roadie
04-10-2010, 05:23 PM
Pull the fuse for 30 seconds to force another recalibration with the new actuator. The position of the controls is irrelevant during a recalibration, but some members have reported better success with them turned off. I have no idea why. Then turn on the key - and don't start the engine if you're curious about what the recalibration sequence does. After 90 seconds or so, when everything ceases moving and the fan stops testing its ranges if you have the digital controls, then you can run the engine and test it out.

daveyboy43
04-10-2010, 05:55 PM
It works perfectly. Toughest part for me was the one screw and the fact that I'm 6'5" trying to work in such a small area. Nothing a cold beer here and there couldn't fix. Hey roadie if you want my actuator p/m your complete address and I'll send it to you.

lonewolf1986
04-10-2010, 07:00 PM
i replace the actuator and now it is stuck in vent and wont switch to floor i can see the actuator gear moving but the door is not moving what could i try next

this is the door i bought was told its the right one
ACDelco 15-73596 Actuator Assembly

the roadie
04-10-2010, 07:11 PM
How can the gear move and the door doesn't? They aren't connected? Did you press the actuator back on the shaft in the same position that the other one came off? You might have to use a trick from another poster if you didn't mark the shaft before removal - figure out where the shaft should be when you put it back on, then move the actuator using the control when it's removed from the shaft. Put it back on when they match what you expect them to look like. You might need to examine the actuator and the door shaft to get them at one of the end points so they match. But I haven't done this for a while so I'm not explaining it as well as somebody with a better memory.

lonewolf1986
04-10-2010, 07:50 PM
i took it back off and messed with the door when i move it the door automatically goes back to the vent position, so with the actuator off i turned the switch to vent only and tryed putting it on and the same thing occurs, also the vent even stays on when the defrost is on.

fnloco
04-10-2010, 09:27 PM
Hey Roadie, I installed a blend door actuator today on the wife's 03 TB and cannot seem to get it to work correctly. I seems like it is a tooth off. Can you give me a quick rundown on the install and calibration sequence? Thanks in advance for the help.

rfarrah
04-12-2010, 08:38 AM
Worked on the passenger actuator yesterday. The steel brace made it impossible to remove without destroying the actuator in the process - I just couldn't get it off the "stick". I was hoping to repair it ala Roadie, but it's in too many pieces at this point. It's too bad - the gears looked okay. :suicide:


In any case, thanks for all the help here, guys.

One tip I can offer: At the far end of the passenger-side dash (facing the door) is an access panel. If you remove it you can look through that hole and actually SEE the stupid little screw that's preventing you from getting this thing loose, rather than having to work on it blindly.

Dewaholic
04-12-2010, 03:18 PM
Worked on the passenger actuator yesterday. The steel brace made it impossible to remove without destroying the actuator in the process - I just couldn't get it off the "stick". I was hoping to repair it ala Roadie, but it's in too many pieces at this point. It's too bad - the gears looked okay. :suicide:


In any case, thanks for all the help here, guys.

One tip I can offer: At the far end of the passenger-side dash (facing the door) is an access panel. If you remove it you can look through that hole and actually SEE the stupid little screw that's preventing you from getting this thing loose, rather than having to work on it blindly.

Do you still have your bad actuator? If so the only thing wrong with mine is the gears. I could possibly swap them out. Let me know.

Dewaholic
04-14-2010, 02:33 PM
If anyone has a bad mode door actuator and doesnt mind parting with it, let me know. I need the gears inside, it works other than that. I will pay shipping and maybe alittle more if you want. Thanks.

sawzall
04-17-2010, 02:41 PM
I just replaced my mode actuator due to the dash vents not working; it wasn't too bad of a job; you just need to be patient and smart as you work.

First you need to find out what part number to order; just call the local GM dealer. you will need to give them your VIN; the P/N I used was 89018675 and I got it from www.parts4chevys.com for $46.33 which was alot cheaper than the dealership.

Remove lower dash covers. The actuator is located behind the middle portion of the dash; if you lay on the floor and look to the left you will see it.

Remove gray air duct as shown in pc #53; just pull it from it's endpoint; this way you can get to the actuator better.

There's 2 actuators; you want the one with the white gear coming out the side; it's the lower one in pic #52. You will need a 5.5mm socket to get the 2 screws out; be careful not to drop the screws; take your time.

Pic #46 shows the actuator; the two horizontal holes are where the screws mount; the other one close to the wire connection has a dowel that helps locate the actuator. You will need to adjust the white gear shown in pic #46
to be at the same location as the gear on the actuator you removed in order for it to go back in correctly. There are 3 marks on the back of the plastic housing (as seen in pic #46) and also slots in the metal part of the gear drive, the top slot is in the 1'oclock position in pic #46. Be sure your new actuator gear position matches the old and it will drop right in. I put the screws in the socket and then wrapped electrical tape around them so the screw wouldn't fall out during assembly. The whole thing took me 45 minutes.
The vents now work like a charm and I saved a bunch of coin!

You can doooo eeeet!

THanks for this info! I'm tackling this job as I write this but need to verify. From pic #52, the mode door actuator is at the bottom of the pic but its actually the higher of the two right? Closest to that black shaft way up underneath?
On my 2003 Envoy SLE, only the top one has the bottom dowel in the hole, the lower, angled actuator doesn't have anything in the hole.

sawzall
04-17-2010, 04:36 PM
OK, just finished my mode door actuator replacement.

Here are my NOOB observations, which probably are somewhere in this 40 page thread already but anyway...

Followed Roadies directions.

I very carefully pulled the plenum/vent tube fastener straight down until it popped off. That plastic is too thin for my taste, didn't want to schnap it.

Two screws hold the under-dash cover on on mine. Disconnected the 3 wire harnesses, all of which attach differently to the cover.

I was able to remove my actuator screws with the 7/32" socket by hand, same for the install. This really helped not having to wedge a ratchet up in there. They weren't and aren't loose, just used some HD finger power.

For the aligning, I would recommend NOT ever turning the gear by hand. It wil start to skip and most likely grind down those little teeth on the plastic shaft. Plug it in and turn on the ignition to reposition it.
I tried repositioning the new unit as the old one was but that didn't work, Dash Vent only in any mode, gears weren't meshing. I realized that the mode door sort of flops down with gravity to the bottom which is Dash Vent only. Not wanting to muck with manually positioning the door while trying to instal the actuator, if that's even possible, I plugged the new actuator in unmounted and set the control to Dash Only. At that point the gear is "fully erect" like a wing on the actuator, sticking pretty much straight up. Then I loose mounted it to make sure everything was flush, no gaps at the screw holes between actuator and mount, no wobble vertical or horizontal. Then re-screwed it in using some scotch tape on the socket/screw and fired it up. Everything works just as before!
Not having dash and rear AC in AZ is brooootaaalll, its getting to be that time.
I also noticed that during the time the actuator was broke, it seemed the AC was always on even though the light wasn't on the button. Is this default windshield vent behavior? It just blew way colder than outside air with AC switch off, froze up the feet a bit.

Thanks to the dozens of you who also contributed to this thread. I don't know how much I saved but I'm sure at least 3 bills vs. going to dealer for the fix.

dean
04-17-2010, 05:22 PM
Mine just went out on my 06 Envoy. Guess I know what I am doing this week. Printed the first post with photos and just read the last post. Hopefully this goes well.

mctrailblaze
04-22-2010, 08:13 PM
Hey guys in the middle of tackling this project. However, I think I overlooked a pretty important symptom. Only way you learn is trial and error right? :)

Anyway, I am running a '04 Trailblazer LS 6 cyl.

Got the door mode actuator out, popped in the new one, and it wasn't really doing anything. Did the HVAC B fuse reset procedures at least 3 (maybe more) times. Then I let the actuator hang while I did a reset to see if the gear would move at all. It did not. Also moved the door knob on the HVAC control unit, gear did not move at all.

In regards to the control unit, I am not sure if this is normal or if this is my problem, however when you turn the fan speed knob it kind of clicks to each position. However when you move the door knob it moves like 4 clicks to each mode not just one. Is that normal, or a sign of a bad controller?

The HVAC system is plagued with a few issues. #1 the door mode problem, #2 can get A/C and cold settings fine on whatever vent I manually move the door to, however when I move to heat setting (all settings in heat), I do not receive heat.

I pulled the part # from Roadie's diagram AC-Delco 15-73596.

I am assuming this is the right part #. If not someone please let me know what the correct part # is.

Lastly, if it's not a problem with the part, then it must be the controller. I am assuming in regards to the heating it is likely the tempature actuators have failed as well, there has been alot of battery disconnecting on this vehicle cause I have had to do alot of things to it, it also has a brand new tranny :p So it would make sense if those actuators have failed due to the battery being disconnected more times then I can count.

If anyone can give me any ideas of things I should check before I order this new controller that'd be great. Going to go take a nap before I go to work so I will hopefully talk to you guys later tonight or in the morning. Thanks a bunch.

Addendum: It's a manual HVAC controller, all knobs no digital. There's also a rear cab controller in the back of the center console. Hopefully that's all the info anyone would need to know about this issue.

STECH
04-22-2010, 08:43 PM
03Huggy, what prompted you to replace the Actuator? Currently my wifes '02 Envoy makes a clicking sound when you changes modes, like from the upper vents to the lower vents, etc. The air still comes out, but it makes the clicking noise like it is binding as it is changing positions. I didn't know if this is what you were experiencing or not?
Thanks

my 02 envoy was doing the same thing, if you get under dash on drivers side & look up you will see there is more than 1 of those actuators there. if you turn the hvac selector back & forth while laying your hand on actuator you can tell which one is is clicking/clacking. on my envoy the failed actuator was trapped behind aluminum frame. i was able to remove cover on existing actuator & took gears from new one & installed into it. the gears were striped. took about 20 minutes & has been working perfectly for past 35,000 miles

mctrailblaze
04-23-2010, 04:46 PM
Anyone got any input on my last post? :(

the roadie
04-23-2010, 11:44 PM
I have the digital controls, so I'm not certain of the manual one's operation except by the schematic. It would save a LOT of time if you could find a local trailvoy-owning buddy to trade modules with.

Dewaholic
04-24-2010, 11:50 AM
If you guys dont mind, insted of throwing away your old ones please let me know if I can have them. I will pay for shipping. I just need the gears inside if they are not broken. Mine still works but has broken gears. I will pay you $10 or so if need be.

omega7398
04-25-2010, 05:49 PM
I am new to this forum, but i am also having a problem with air not blowing out my front vents. I have a 2004 Trailblazer with manual controls. I thought that a new mode actuator would solve my problem because I was getting air everywhere else except the front dash vents. I put in the new actuator and it did not work at all. I tried pulling the fuses to recalibrate the HVAC system, but still no luck. When I put the old actuator back in and turned on the key the old actuator moves, but I still get no air from my dash vents.
Someone told me to replace my recirculation actuator, but i do not see how that would be related to the problem of my dash vents not working. If someone knows what i can try next i would greatly appreciate the help. Thanks.

Rico
04-27-2010, 01:42 PM
Hi all! New to the forum. I was able to follow the great directions on how to replace the mode actuator. Replaced it myself and saved $300 when compared to the dealers quote. Hoever, now I have air out the dash vents but no air out the floor vents. Also, dash vents still blow when I switch to defrost or other settings. I have a read few posts (recalibration or remove and manually adjust) addressing this issue but nothing definitive. Any help and direction would be greatly appreciated.

POLARIS600
05-06-2010, 12:01 PM
:)I just replaced my mode actuator due to the dash vents not working; it wasn't too bad of a job; you just need to be patient and smart as you work.

First you need to find out what part number to order; just call the local GM dealer. you will need to give them your VIN; the P/N I used was 89018675 and I got it from www.parts4chevys.com for $46.33 which was alot cheaper than the dealership.

Remove lower dash covers. The actuator is located behind the middle portion of the dash; if you lay on the floor and look to the left you will see it.

Remove gray air duct as shown in pc #53; just pull it from it's endpoint; this way you can get to the actuator better.

There's 2 actuators; you want the one with the white gear coming out the side; it's the lower one in pic #52. You will need a 5.5mm socket to get the 2 screws out; be careful not to drop the screws; take your time.

Pic #46 shows the actuator; the two horizontal holes are where the screws mount; the other one close to the wire connection has a dowel that helps locate the actuator. You will need to adjust the white gear shown in pic #46
to be at the same location as the gear on the actuator you removed in order for it to go back in correctly. There are 3 marks on the back of the plastic housing (as seen in pic #46) and also slots in the metal part of the gear drive, the top slot is in the 1'oclock position in pic #46. Be sure your new actuator gear position matches the old and it will drop right in. I put the screws in the socket and then wrapped electrical tape around them so the screw wouldn't fall out during assembly. The whole thing took me 45 minutes.
The vents now work like a charm and I saved a bunch of coin!

You can doooo eeeet!

This was agreat post and worked out great for me. thank you this seems like an informative site kee up the good work and share experiences.:grouphug:

lonewolf1986
05-07-2010, 02:01 AM
well i figureed my problem i ordered the right part number but didnt realize they sent me the wrong part.

tsutaz
05-08-2010, 09:41 AM
I followed instruction from #1 post. Overall job took me 1 1/2 - 2 hrs. Took me a bit to figure out how to adjust the gear to match the old one. The gear was in the 11 o clock position, I firmly grabbed the gear and rotated to 1o clock position, carefully and slowly. Installing the part back in place was a little painful. Getting the actuator to stay in put while you manage to get the screws back up and screw them in was a bit tricky. Not a lot of room to work. I used electrical tape to secure screws to socket as recommended. I did not take my gas pedal off as some others have done not did i take the seat out, but I did make sure it was as far back as it could go.

I didn't have time to order online so I went to dealer and part cost me 77 bucks.

Instead of using 5.5mm I used 7/32 socket. I also purchased a new palm Kobalt ratchet kit from Lowes, 15 bucks.

Oh, this job was on a 2005 TrailBlaizer EXT LT. This forum saved me lots of money. Thanks to all who contribute!!!!!

Taz

tsutaz
05-10-2010, 11:52 AM
Well, after I fixed this issue Saturday morning on the 05 TB, everything seemed to fine. the family didn't drive the vehicle much on Saturday, Sunday I didn't drive it at all, Wife used it around town and such, still no problems. It was kinda "chilly" here on Sunday, no not much need for air flow. Anyway, now it's Monday morning and AIR will not blow out of the bottom. Stuck on the front vents now and on top. UGH!!

I guess disconnecting the battery to reset the actuator is worth a try.

Any ideas please?

Thanks
Taz

BADMOD97
05-12-2010, 03:05 PM
This is my first post and I wanted to say thank God for this site!!! Old story here, I changed the battery and of course the air quit blowing through the dash vents and the passenger side defroster and floor vents were blowing hot. I read this entire thread several times over and decided to "fix" the problems. I did not replace the mode actuator or the passenger temp actuator. I simply unpluged each actuator and turned the metal part of the gear drive on the mode actuator until I got air through the driver side dash vents. I then turned the passenger temp. actuator until the air blew cold through the passenger side dash vents and the rear air. The reason I did not replace these are my finances are extremely tight (I have two daughters in college and two more in high school). I guess when it gets cold I will have to deal with the passenger temp. actuator (I sure don't look forward to replacing that as there is very little room to work with).

This was on my daughter's 2004 Trailblazer.

cynimaddict
05-14-2010, 09:23 PM
I read through this and other links when I found my air was only coming out the defrosters and the floor. I tried pulling the fuses for the HVAC and letting the system reset with the key in the "on" position (at night with the doors closed you could hear them one at a time resetting) was hopeful that would solve it, but problem remained.

I was ready to order the part, but finances are tight. The next day it got a little warm here and I decided to test what I had while out running errands. The EXT's have the rear air controls, which I turned up all the way, and within about 3 minutes I was freezing.

I'm gonna roll with it until I have the time and money to mess with replacing the actuators or the problem gets worse and I start roasting in the summer heat.

Just something for those of you that are noticing the air won't come through the vents, but may get the impression that you have no air at all.

*SOME folks are having an issue where the air won't come out of the dash vents AND won't blow cold.

my:m2:
http://hphotos-sjc1.fbcdn.net/hs637.snc3/31981_1350581439650_1084796994_30907683_1826852_n. jpg
http://sphotos.ak.fbcdn.net/hphotos-ak-snc3/hs637.snc3/31981_1350584279721_1084796994_30907694_4454346_n. jpg

2001FZ1
05-15-2010, 09:11 AM
Difference in temperature between driver's side and passenger side does not always mean a bad actuator or bad temp sensor!

I took my Rainier into the shop this week for this problem. The cause was that it was low on refrigerant. The A/C now blows very cold on both sides. The mechanic said I most likely have a leak but its very, very slow and he couldn't find it.

How much does a new A/C compressor cost?

the roadie
05-15-2010, 10:57 AM
How much does a new A/C compressor cost?$75-$250 on Ebay. Also check Rockauto if you want a new one with some kind of guarantee.

Dewaholic
05-15-2010, 02:45 PM
In the middle of swapping the mode door actuator. I ordered a new one and trying to put it in. For some reason after i power up the mode door will go to one side to its limit and just stop. It will not respond after that. I will have to remove the cover to unjam the gears and try again. I have done the battery thing. Im going to try the fuses now under the rear seat. I can manual move the door and have it moved to the front vents which mean the actuator is at 1 oclock position I believe but still no help. If any one has any ideas I would appreciate it if you can get to me fast. I have been working this thing for 4 hours now. Thanks.

the roadie
05-15-2010, 03:47 PM
Is it too late to match the position of the new one to where the old one was when you took it off? If you take the cover off and work on the gears, you have to very, very cautious around the blue sensor. It's a potentiometer, like a volume control, but it doesn't have any stops. It can spin around and around. If it's in the wrong position relative to the final output gear, it can spin around and then maximum CW and maximum CCW gear positions aren't accurately reported back to the control module. And then the power-up calibration process fails, and as you see, then the control module abandons talking to that actuator until you pull the fuse. That forces a new calibration cycle when you turn on the ignition again.

It's possible to lose position feedback altogether. I did that accidentally while fixing mine. All I needed to do was press the final gear back further on its knurled shaft so it didn't slip, but I messed up the potentiometer relationship when I unstacked the gear train, and it took me an hour of figuring it out and reassembling it to make it work. And I'm an electrical engineer and understand how it was supposed to work. :o

Dewaholic
05-15-2010, 03:53 PM
Yea I finally figured out the little blue gear about half hour ago. I think I finally have it doing it cal and everything, just have to figure out the right position to put it back in. I was using the position of the old one but with my old one the gears in side exploded so the shaft wasnt turning when I was changing modes when it first happened to figure out why I it wasnt changing. So yea position is lost. But like I said I think I may have it but when I went to try it, my battery died, So I have to wait till the wife gets home so I can jump it. Im in the process of putting on liftgate struts as I type and change the EVAP solanoid.

Will report back once I get a jump and see how it acts.

Dewaholic
05-15-2010, 06:21 PM
Is it too late to match the position of the new one to where the old one was when you took it off? If you take the cover off and work on the gears, you have to very, very cautious around the blue sensor. It's a potentiometer, like a volume control, but it doesn't have any stops. It can spin around and around. If it's in the wrong position relative to the final output gear, it can spin around and then maximum CW and maximum CCW gear positions aren't accurately reported back to the control module. And then the power-up calibration process fails, and as you see, then the control module abandons talking to that actuator until you pull the fuse. That forces a new calibration cycle when you turn on the ignition again.

It's possible to lose position feedback altogether. I did that accidentally while fixing mine. All I needed to do was press the final gear back further on its knurled shaft so it didn't slip, but I messed up the potentiometer relationship when I unstacked the gear train, and it took me an hour of figuring it out and reassembling it to make it work. And I'm an electrical engineer and understand how it was supposed to work. :o

Yep roadie that is exactly what is going on. I worked on it for another hour or so and still couldnt get it. I will have to tackle this tomorrow and see if I can figure it out. I had it once but when i would switch vents to the floor it wouldnt completely turn off the upper vents. So i messed around a bit with it some more and lost it. This is officially a pain now. Oh and so far after about 10 start ups the evap vent solenoid hasnt cleared my SES light, oh yay! :mad::confused:

tyler70t
05-20-2010, 12:04 PM
ok, I bought the new part, installed it and now it seems as if the air comes out up top but when switched over to heat on the floor nothing is coming out. Can I adjust this with a large flathead on the backside of the where the gear goes ?..........................Jeff:bonk:

KNBlazer
05-20-2010, 03:50 PM
ok, I bought the new part, installed it and now it seems as if the air comes out up top but when switched over to heat on the floor nothing is coming out. Can I adjust this with a large flathead on the backside of the where the gear goes ?..........................Jeff:bonk:



no you will need to take it out and visually watch as the gear adjust, once it aligns with the notch, quickly turn the ignition to off...

a_kraker99
05-24-2010, 10:54 AM
Okay I am sure this has been posted a million times but I read through quite a bit and haven't found my answer.
I disconnected the battery like most others on here and now air only comes from the floor and defrost. I wouldnt say that I hear clicking, more like a contant whine while the motor tries to move and nothing happens. Do you think I have a bad one? I tried recalibrating a couple of times but nothing happened.

My question is that if I get a new one how do I make sure I dont break that one too? I understand that I have to put the new one in at the same position the old ones came out. Do it just plug the new one in without installing it, wait for the calibration to do its thing and change the vent mode until it lines up with the old one? What vent mode would that be?

a_kraker99
05-24-2010, 12:53 PM
Quick update on my progress. I got the old actuator out and took a look at it. Gears look perfectly fine. I cant seem to get the actuator to calibrate thought. It will move to the vent position if I pull the fuse while the ignition is on. I am not sure what that means but at least I know that the gears are all working and it moves. However, if I try the calibrate procedure it doesent want to move, It moves all the way to where the gear fan is inwards and stops.
Any tips or advice?

High Roller
05-24-2010, 01:45 PM
[QUOTE=03Huggy;535686] the P/N I used was 89018675 and I got it from www.parts4chevys.com for $46.33 which was alot cheaper than the dealership.[QUOTE]

GMPartsdirect.com GM LIST: $66.12 OUR PRICE: $34.38

How do I get the "our price"? I need to get one. Thanks and great help on this site...you guys have saved me more than once. Usually the same known problems and at the estimaed milage right on time. I gotta do the damn sending unit next....Love our Envoy though....

a_kraker99
05-24-2010, 06:49 PM
I cant seem to get the new actuator lined up to the hvac gear. The hvac gear sort of flops down with gravity to the top vent mode. Where does the gear need to be on the actuator to match this? Any tips?

High Roller
05-26-2010, 08:46 AM
What I did last night to fix this was to plug the actuator in while it was not installed and set it to dash vent since that seemed to be the location the door was in manually (due to gravity). It went right in. I spent 2 hrs cussing like a sailer because of this. So now it is in but the dash vent wont totally shut off. I tried the disconnect wiring/battery/etc and nothing changes. Another 2 hours go by and take it out 4 more times trying differieng way s of doing it. Put it all back together madder than hell.

ANYONE PLEASE HELP!!! I dont want to take it to the stealership after spending this much time on it. I hated to do teh battery disconnect to reset this since that is what caused this issue in the first place. PLEASE PLEASE PLEASE help...

a_kraker99
05-26-2010, 11:17 AM
What I did last night to fix this was to plug the actuator in while it was not installed and set it to dash vent since that seemed to be the location the door was in manually (due to gravity). It went right in. I spent 2 hrs cussing like a sailer because of this. So now it is in but the dash vent wont totally shut off. I tried the disconnect wiring/battery/etc and nothing changes. Another 2 hours go by and take it out 4 more times trying differieng way s of doing it. Put it all back together madder than hell.

ANYONE PLEASE HELP!!! I dont want to take it to the stealership after spending this much time on it. I hated to do teh battery disconnect to reset this since that is what caused this issue in the first place. PLEASE PLEASE PLEASE help...

Here is what I found out from a guy I know at the dealer. Mine is working perfect now. If you buy a new actuator you don't need to move the gears at all. It should line up exactly the way it should. Just make sure your HVAC gear in the vehicle is fully clockwise (blowing out the vents).
I made the same mistake you did and tried calibrating while the actuator was not installed. You cannot do that. But if you did, you will need to move the gears back to the correct position. To do this you can take the cover off the actuator as shown below.
http://i197.photobucket.com/albums/aa244/tiff_andy/forsale/2010-05-26102037.jpg
Make sure you don't let the large gear and the small blue gear skip any teeth while messing with it. You might want to make a mark just in case.
Take the medium sized grey gear out as shown.
http://i197.photobucket.com/albums/aa244/tiff_andy/forsale/2010-05-26102100.jpg
Then you can spin the large grey and blue gear to where they need to be. Line the blue gear up exactly like it is shown below.
http://i197.photobucket.com/albums/aa244/tiff_andy/forsale/2010-05-26102416.jpg
considering you haven't skipped any teeth in the gears from the previous calibration attempts, your actuator wing should be in this position.(note the metal tab on the metal shaft and the small groove in the plastic)
http://i197.photobucket.com/albums/aa244/tiff_andy/forsale/2010-05-26102522.jpg
Once everything is lined up exactly like that you should be able to put it back together and install the actuator. Pull your HVAC B fuse for a minute and put it back in. Turn the key to on but don't start the car. Don't touch your HVAC controls. You should be able to see the metal part on the back of the actuator move from one side to the other. Then it will be calibrated.

High Roller
05-26-2010, 12:12 PM
Once everything is lined up exactly like that you should be able to put it back together and install the actuator. Pull your HVAC B fuse for a minute and put it back in. Turn the key to on but don't start the car. Don't touch your HVAC controls. You should be able to see the metal part on the back of the actuator move from one side to the other. Then it will be calibrated.


Not to doubt you, but it looks like that's where it was when I started and it would not seat down on the center shaft support, bolt hole supports and the pin locator. It rocked side to side (bolt hole to bolt hole) like it was not setting down. I would hate to go through all this and be right back where I was. Do you truely think this will do it?

a_kraker99
05-26-2010, 01:14 PM
Not to doubt you, but it looks like that's where it was when I started and it would not seat down on the center shaft support, bolt hole supports and the pin locator. It rocked side to side (bolt hole to bolt hole) like it was not setting down. I would hate to go through all this and be right back where I was. Do you truely think this will do it?

That is what worked for me. Just make sure the gear for the fan door gear in the vehicle is turned all the way clockwise so that the air blows out the vents. Without the actuator in it usually goes to that postion from gravity anyways. I know it is a pain in the rear, trust me, I am still sore from the crazy positions I had to get in to get at the thing.

Mark_Texas
06-04-2010, 06:34 PM
I couldn't get my rear HVAC actuator to come off the shaft. I wasn't sure if there was a release mechanism on it, and I was afraid that I was going to break the shaft if I pulled too hard. I finally sprayed some WD-40 on the shaft, and that did the trick. It looks like it is fixed now.

Mark

nateb21
06-05-2010, 10:43 AM
OK I know this has been beaten to death but I replaced the actuator after not having vents for a few weeks. Not a horrible job but not real fun either. Got it all replaced and now I can't get the vents off, I can use defrost and vents but not the floor. I fiddled with moving the door by hand and then trying to make it work with the actuator but no go. After about an hour of screwing with it in the hot garage I gave up and was just happy to have vents but it will bother me as time goes on so how do I go about fixing it?

pete240z
06-05-2010, 06:31 PM
OK not real fun either. Got it all replaced and now I can't get the vents off, I can use defrost and vents but not the floor. I fiddled with moving the door by hand and then trying to make it work with the actuator but no go. After about an hour of screwing with it in the hot garage I gave up and was just happy to have vents but it will bother me as time goes on so how do I go about fixing it?

I am in the same boat. 3-1/2 hours of removing, adjusting, resetting, and reinstalling. I have it down well and I have the same problem as above. I finally just gave up and put it all back together. No floor direction.

aaaaarrrrggghhhhhh. This tops the crap I had to put up with my wife's 1986 Grand Am SE - (first V6 model) - fun times.:mad::mad::mad::o:o

pete240z
06-05-2010, 06:34 PM
Here is what I found out from a guy I know at the dealer. Mine is working perfect now. If you buy a new actuator you don't need to move the gears at all. It should line up exactly the way it should. Just make sure your HVAC gear in the vehicle is fully clockwise (blowing out the vents).
I made the same mistake you did and tried calibrating while the actuator was not installed. You cannot do that. But if you did, you will need to move the gears back to the correct position. To do this you can take the cover off the actuator as shown below.
http://i197.photobucket.com/albums/aa244/tiff_andy/forsale/2010-05-26102037.jpg
Make sure you don't let the large gear and the small blue gear skip any teeth while messing with it. You might want to make a mark just in case.
Take the medium sized grey gear out as shown.
http://i197.photobucket.com/albums/aa244/tiff_andy/forsale/2010-05-26102100.jpg
Then you can spin the large grey and blue gear to where they need to be. Line the blue gear up exactly like it is shown below.
http://i197.photobucket.com/albums/aa244/tiff_andy/forsale/2010-05-26102416.jpg
considering you haven't skipped any teeth in the gears from the previous calibration attempts, your actuator wing should be in this position.(note the metal tab on the metal shaft and the small groove in the plastic)
http://i197.photobucket.com/albums/aa244/tiff_andy/forsale/2010-05-26102522.jpg
Once everything is lined up exactly like that you should be able to put it back together and install the actuator. Pull your HVAC B fuse for a minute and put it back in. Turn the key to on but don't start the car. Don't touch your HVAC controls. You should be able to see the metal part on the back of the actuator move from one side to the other. Then it will be calibrated.

I have to do this? I can't wait!!!!! I need to wait for cooler weather!!!!:bonk::bonk::bonk:

jimmyhd
06-15-2010, 08:01 PM
I am in the same boat as nateb21. I have a 2004 TB. I have been trying to get to the actuator but am confused right now.

Imagine not laying under the dash and looking at the driver side of center console where the actuators are mounted. When I look I see three. The one on the far right is down towards the actual floor and I am assuming that is not it. There is one up high on the far left, close to the firewall. Then there is one next to this, technically located or identified as the center actuator (as least in my terms). Does anyone know which one it is? People keep saying it has a white gear but not one of these three has a white gear coming out of it.

Second, how do you reach the little PIA? There is all sorts of stuff blocking them. I started taking out the dash tonight but just stopped because I am hoping there is an easier way.

Any help would be appreciated.:suicide::bonk:

coolcloo1019
06-24-2010, 09:04 PM
For any of you guys replacing this on your 02 model. The actuator that I received had the white gear on it. You'll notice when you take out your old actuator that you don't have that gear. I was a bit concerned at first as I waited a week to get the part and had the underside of the dash apart. I wasn't about to send it back.

Pull the white gear straight out of the actuator. It's really in there but just pull straight and it will come.

I then had to open up the actuator and adjust the gears inside just like the pics on this page up above show. I then had to adjust the shaft under the dash to match up to the actuator and it slide right on. Put your 2 screws back in place, hook the plug back up and then go to the rear fuse box and pull HVAC B for 30 sec. Replace the fuse, turn the ignition to "on" while under the dash watching the actuator to make sure it's working properly. It will take 30 sec - 1 min to cycle. After that, put it all back together.

Valkyrierider
06-29-2010, 03:48 PM
After more searching, found this thread, wondering if anyone has pics of the rear temp Actuator Assembly. Going to try and do this this weekend.

the roadie
06-29-2010, 10:36 PM
http://www.roadie.org/rearactuators.jpg

SAR85
07-08-2010, 10:53 AM
Here is what I found out from a guy I know at the dealer. Mine is working perfect now. If you buy a new actuator you don't need to move the gears at all. It should line up exactly the way it should. Just make sure your HVAC gear in the vehicle is fully clockwise (blowing out the vents).
I made the same mistake you did and tried calibrating while the actuator was not installed. You cannot do that. But if you did, you will need to move the gears back to the correct position. To do this you can take the cover off the actuator as shown below.
http://i197.photobucket.com/albums/aa244/tiff_andy/forsale/2010-05-26102037.jpg
Make sure you don't let the large gear and the small blue gear skip any teeth while messing with it. You might want to make a mark just in case.
Take the medium sized grey gear out as shown.
http://i197.photobucket.com/albums/aa244/tiff_andy/forsale/2010-05-26102100.jpg
Then you can spin the large grey and blue gear to where they need to be. Line the blue gear up exactly like it is shown below.
http://i197.photobucket.com/albums/aa244/tiff_andy/forsale/2010-05-26102416.jpg
considering you haven't skipped any teeth in the gears from the previous calibration attempts, your actuator wing should be in this position.(note the metal tab on the metal shaft and the small groove in the plastic)
http://i197.photobucket.com/albums/aa244/tiff_andy/forsale/2010-05-26102522.jpg
Once everything is lined up exactly like that you should be able to put it back together and install the actuator. Pull your HVAC B fuse for a minute and put it back in. Turn the key to on but don't start the car. Don't touch your HVAC controls. You should be able to see the metal part on the back of the actuator move from one side to the other. Then it will be calibrated.

This worked perfectly for me. Between the original directions and the hopeful posts before this, I was able to fix my issue without even replacing the part (chalk another one up for "big white gear slid off drive shaft"). Took me three or four times of messing with it before I came across the above post but after I lined everything up, it worked perfectly.

A note for all those who "fix" the problem but then get air out of only the dash vents: follow the above steps for alignment of the external white gear and it should all line up properly and work. I had the same problem after reinstalling but following the above directions fixed everything.

Thanks to all who helped out!

mzobrist
07-10-2010, 09:33 PM
I have been studying these posts related to HVAC door mode actuator replacement for months now. I feel like I have a pretty good idea of how to get this done. One small problem.....in the original post #1, there are references to picture 52, 53, etc. I only see three pictures attached. Am I missing something? I would like to see the step by step posted by 03Huggy before beginning my project. Will someone please help? Thanks.

SAR85
07-10-2010, 09:39 PM
I have been studying these posts related to HVAC door mode actuator replacement for months now. I feel like I have a pretty good idea of how to get this done. One small problem.....in the original post #1, there are references to picture 52, 53, etc. I only see three pictures attached. Am I missing something? I would like to see the step by step posted by 03Huggy before beginning my project. Will someone please help? Thanks.

The numbers refer to the filename of the pictures. There are only three. And "lower" refers to the lower actuator in the picture, not necessarily in the vehicle.

Menthol
07-11-2010, 05:19 PM
I have been studying these posts related to HVAC door mode actuator replacement for months now. I feel like I have a pretty good idea of how to get this done. One small problem.....in the original post #1, there are references to picture 52, 53, etc. I only see three pictures attached. Am I missing something? I would like to see the step by step posted by 03Huggy before beginning my project. Will someone please help? Thanks.

Hover you mouse over the pic without clicking, you will see the file number of the pic as # 0052 0R 0052 ect.

mzobrist
07-12-2010, 10:55 PM
Hover you mouse over the pic without clicking, you will see the file number of the pic as # 0052 0R 0052 ect.

Ah, OK. :duh::duh:

BigJob
07-17-2010, 08:20 AM
Finally ordered my actuator from rockauto.com. $45.15 shipped. Hopefully I can follow this thread enough to get it installed easily. :)

Mikie2000
07-19-2010, 12:42 AM
OK, I have read all 38 pages of this thread. I think I have a unique problem. I have removed the dash and most of the HVAC ducts so I can look directly down into the air plenum. I can see both drivers and passenger temp door in motion. the driver door closes and it still has warm air coming from the air duct on the drivers side, the passenger side closes and I got cold air from passenger side. I turn the passenger side to 90 deg. and place on upper duct ..the Driver side gets a little cooler but still no avail. My whole problem started with the disconnected Battery syndrome :duh: Wish I would have known where that would lead... :crazy: but I digress... is there another door that would allow for heated air to enter the duct work. and is there a diagram that would allow me to see the airflow within the system? I have allowed it to "calibrate " to its little hearts content about 5 times but still end up with warm air. I know the actuators both have good teeth as they have been visually inspected. any help with this would be appreciated

Drivers side vent is cabin temp air when on recirculate and outside temp air when not .

BigJob
07-20-2010, 10:17 PM
For anyone having the following issue during the installation of the actuator... please read.

I installed my new actuator, but didn't read ahead enough when it said to match the new actuator gear position to the old one. Well I had already had the old one apart looking at it, so I had to try to set the new one based off of memory :(

Anyway, installed new actuator and was excited that my face vents were finally working... but not excited that they wouldn't turn off now. So I tinkered with it...

The white gear on the actuator connects with a black gear in your vehicle, this gear is the door position (obviously.) The solution I found was to set your HVAC control to face vents, make sure the black door-gear is all the way up, and set the actuator to the vertical (12 oclock) position (may need adjustment within a couple millimeters to get it to lock in right.) This worked for me, everything works as normal now. Took me quite a while to figure out, but the removal/install was a breeze.

This solution may have already been posted, I haven't read through everything so I apologize in advance if I'm late, and sorry I have no pics :(

I hope this can help anyone having issues installing.

markobrady
07-21-2010, 07:22 AM
I have the same vent actuator problem but I have a 2004 Envoy XUV V8. My question is it the same part as the one in the V6?

mitsusport2000
07-21-2010, 12:50 PM
I actually completed this but I think I turned my mode actuator too much because now it doesn't come out of my floor vents.

dheezknutz
07-22-2010, 04:38 PM
Remove gray air duct as shown in pc #53; just pull it from it's endpoint; this way you can get to the actuator better.


Sorry to open this up, but since it seems like there is no end to the questions on this project, I'll add my questions. How in the world do I get the air duct out of the way. It comes out of the center console and goes up and over the gas pedal. I can't seem to get it out of the way to see what I am doing.

I am also starting to slam doors and swear. Usually that helps but it doesn't seem to be helping me today. :bonk: I'd love some recommendations. Thanks to all. This site is a savior.

Edit: For more info. I have the lower dash covers off. I pulled down on the air duct and it is loose but I can't really move it in any direction to any benefit. The rainier has the digital AC controls and blows at the feet, windshield vents, and rear. Nothing at the center face vents.

Edit2: So I finally got the actuator out. I can't seem to get the new one in. I suppose not being a fat guy with fat hands would help but I can't figure it out. I matched the new one up with the old one but it just won't seat all the way. To match them up I did what was suggested and hook it up to the connection, turn on the ignition and turn it off when it matched up. If it is off even a tiny bit will it not fit. It is really hard to see what the tolerances are in that tight space.

I'm now done for the night because we have a birthday to get to and work tomorrow. Thanks for any information.

Nomad
07-22-2010, 10:43 PM
I have been unable to adjust the passenger side temp for a few months now. It would click if I set it anywhere other than about 75% of the way to full hot, so I set it there and left it. Now it is well into the 90s out and the drivers side alone isn't enough to keep me cool. I am attempting to change the passenger side temp actuator and not having much luck. I've tried the fuse 36 reset twice with no luck. The first time, the actuator appears to have moved slightly (perhaps 20 degrees of rotation if that) but the second time it didn't move at all. I've done a fairly thorough search but the only post I can really find dealing with how to actually change the passenger side actuator is this one (http://forums.trailvoy.com/showthread.php?t=58780&highlight=temp+actuator). I don't really want to cut that support, but I guess I'll do whatever I've gotta do. Is there any way to change this part without cutting? I've started disassembling the dash to see if that metal brace is part of an assembly that can be unbolted, but after seeing this picture from the roadie, I'm not too sure I should continue:

http://www.roadie.org/dash03.jpg

Even at that level of disassembly, the brace is still there. Should I just start hacking at the brace like dougbaker78 did? Any other options?

Nomad
07-26-2010, 07:51 PM
OK so after disassembling the dash a good bit more than necessary, I gave up and broke out the Dremel. I cut the brace enough to allow access to the hidden screw and removed both screws. The actuator pulled away from the shaft easily, but did not quite clear the shaft enough to get the actuator out. It would flop around in any direction easily, but the shaft was still inserted ever so slightly. After pulling on the brace and moving the actuator every way I could think of, it finally popped out. The part number on the actuator is 16163982, and after searching that PN it appears to have been superseded by 89018365. These numbers do not match the roadie's PN listing, but I think that is because of a change in the style of actuator in later years? The best price I can find online is around $125, and O'Reillys had one for $145 in stock locally (Dorman 604-106). The dealer wanted around $185 if I remember correctly. I've got the new part now but still haven't put everything back together. I opened up the original and found that the large output gear that actually turns the shaft was split from the center out to one of the valleys between two teeth. At first glance, everything looked fine as the split was hidden beneath another gear, but once I began disassembling the gear train, it was quite clear what had broken. Hopefully the other actuators don't follow suit...

nate4672
08-09-2010, 12:57 PM
Hey guys, I just finished doing this on my 04 envoy.... The stealership wanted 165 bucks for the part and 80 bucks per hour for 5.5 hrs at 95 bucks an hour... I just did this in 45 min and got the part for 45 bucks... This is cake if you follow the instructions on this thread and be patient... Thanks to everyone for the advice and knowledge!!!!!

KNBlazer
08-09-2010, 04:27 PM
Hey guys, I just finished doing this on my 04 envoy.... The stealership wanted 165 bucks for the part and 80 bucks per hour for 5.5 hrs at 95 bucks an hour... I just did this in 45 min and got the part for 45 bucks... This is cake if you follow the instructions on this thread and be patient... Thanks to everyone for the advice and knowledge!!!!!


The service guy at your dealer is an idiot... as far as I know those 5.5 hours were applicable to the 02 and maybe 03 Trailvoys, but as of the last time I researched this job, it was far less time as there was a tool that facilitated the quick swap of the actuator...

drepp001
08-13-2010, 09:22 AM
Only thing I would add is that you ensure you're getting the correct replacement part. A number of local auto parts suppliers were trying sell me the right hand side unit ($140 US) vs the left hand side ($40 US). I found the correct part on Amazon.

RSK
08-21-2010, 11:47 AM
Has any one changed the temp actuator for the passenger side on an 02 envoy? I went to the dealer and they estimated me $900. I would rather do it my self if possible. Is there an easier way of doing it then tearing into the dash completely? Thank you for any help.

KNBlazer
08-21-2010, 09:58 PM
Has any one changed the temp actuator for the passenger side on an 02 envoy? I went to the dealer and they estimated me $900. I would rather do it my self if possible. Is there an easier way of doing it then tearing into the dash completely? Thank you for any help.


I believe your model year falls under the adapter that you can either purchase or make from items purchased at your local hardware store... read through this post...

the roadie
08-22-2010, 09:47 AM
... I went to the dealer and they estimated me $900. ...Those finely trained fellows aren't reading the memos that came out maybe FIVE YEARS AGO that said there was a new special tool that means they don't have to disassemble the dash anymore.

I would have to be a terribly cynical and suspicious person to think that this dealer KNEW about the new procedure and labor standard to use, but quoted the higher price anyway, in case the customer had deep pockets and could afford the $900.

apcapt
08-26-2010, 02:08 PM
We took min apart to see what the issue is and they use gears with very fine teeth. On mine a couple of the teeth were missing. The other thing you can do is if you don't use the floor vents then just unplug the actuator and manually move it until the air is coming out the vents and then just leave it unplugged. This is what I will do next time as I never use the floor vents anyway.

What I'm doing. I just pulled the Actuator the front vents started working which is what I was fixing to begin with. But being the anal person I am. I'm ordering the part.

wkdpanda
08-26-2010, 04:30 PM
This is exactly what has happened to my '03 Envoy. Can get defrost or floor, but nothing out the dash.

Part ordered, and will update after replacement

-Andrew

nateb21
09-13-2010, 10:10 AM
Thank you for Trailvoy.com!! It finally cooled off enough for me to want to attempt to adjust my actuator so it would get off of the vents. Took me a couple tries and a few words that the neighbors didn't want to hear but it is all good now. To everyone who has contributed to this post, thank you, to all who look at it for guidance, trust it, it may take a couple tries but you can do it and save a lot of money! Thanks everyone!

rwlc5
10-12-2010, 12:30 PM
Where are the 53 pictures located showing how to install the part?

Bummed TB Owner
10-22-2010, 03:24 PM
My mode actuator failed and I replaced it a year ago, but it appears I did not have it in the correct position because I only get air out of the defrost or dash vents. I plan to try reinstalling soon to see If I can get it right. The mode door is spring loaded so I can only get it to stay in one position, so I plan on setting the actuator to that position and reinstalling it. I plan to put the mode door into a floor position manually with he actuator out and then with the actuator uninstalled, but with the wiring harness connected I will put the control module to floor, which should move the actuator to a position close to where I have the door and then reinstall the actuator. Hopefully all will calibrate correctly and I will have mode selection again. Am I on the right track?

Another question I have is that the air always comes out of the defrost even when defrost is not selected on the control module. This leads me to believe the defrost actuator is also bad regardless of the problems I am having with the mode actuator. Is this a correct assumption?

Bummed TB Owner
11-01-2010, 11:39 AM
I removed and reinstalled my Mode actuator today and am happy to say I got it right this time. Here are some helpful tips. The new actuator should come in the 1 O'clock position. If by chance you didn't have the mode door in the correct position when you initially installed the mode actuator (like me) then do this to get it back to the 1 O'clock position. Remove the actuator, but leave it plugged in. Using the mode control dial on the HVAC control module, change the actuator to the bilevel or floor position, whichever takes the gear to 1 O'clock position. If yours doesn't move to this position, pull the HVAC B fuse(No. 36 for me) and wait a minute and reinstall it, and don't touch the control module for 1 minute. This will recalibrate the actuator limits, and then you should be able to get it to move to the 1 O'clock position.

Before I reinstalled the actuator I moved the mode door to the floor position by manual turning it all the way down. To keep it in the floor position I had to have the HVAC blower fan on, which will hold the door in the floor position. Reinstall the actuator. I then pulled the HVAC B fuse again, put it back in, which recalibrates the limits again, but this time the limits are set by how far the mode door moves. Don't touch the controls on the control module for about a minute until the actuator calibration is done. Reassemble kick panel and you're done.

Works great now! Good Luck

Works great for me now.

Dewaholic
11-10-2010, 04:46 PM
I will have to try this out on Sunday. Mine went out I think at the beginning of the year. I got my new one but lost the position of it, so after a few days of trying I just threw it in my tool box and delt with it coming out of dash only. Now that its start to get cold out and ice on the windshield in the mornings, im tired of scraping ice and would be nice to have defrost back. Hopefully this will work for me.

Bummed TB Owner
11-10-2010, 09:35 PM
Dewaholic, the mode actuator only changes floor to dash vents. The defrost actuator controls the defrost and is located above and to the left of the mode actuator. You may want check and see if the shaft turns when the control module is turned to defrost before removing it. My problem was only with the mode actuator. Good luck!

Not Bummed anymore.

Dewaholic
11-11-2010, 09:41 AM
Yep, your right. Didnt think. Have to many things going on, p0442, mode door actuator, oil change, spark plugs, TB, dirt out of the window, AC cuts on by itself...................

I guess I will take them both out. If my defrost isnt working and it stopped around the same time as my mode door, both when the battery was replaced, then it either broke as well or just needs the recal. I will try both in either case.

boatpimp
11-13-2010, 02:17 PM
My apologies. I am having numerous issues with my '03TB LS. Perhaps they are related, perhaps they are not. Reading the entirety of this thread has generated more questions than answers.
a) I have the Geiger counter clicking sound coming from my dash, middle-behind radio as best I can tell- my ears are questionable. Leads me to believe pass temp actuator, given what I have learned in this thread. This clicking continues when key is removed. I cannot make this clicking stop by removing any fuses, 36 included.
b)I cannot get cold air out of my HVAC, any damper settings, fan setting, manual dual zone control. Compressor button is pressed, light is on, I can hear compressor engage. This problem is ~6 weeks old.
c) Since replacing battery last week, there is some sort of slow drain on battery when key is out. Drains the battery and cannot start car in morning.
d) Lady friend tells me that when she borrowed car, string a mardi gras beads went down defrost vent on dashboard. 3 months ago.

-I think my mode actuator is fine, I turn the knob, air comes out of the desired vents. But the air is always hot, despite settings. Perhaps this is incorrect.
- I have pulled every fuse in the car (underhood and LR seat) and it either I heard clicking or sparked the negative ground post. This is quite puzzling.
-My thought would be temp actuator, but don't know which one as I can't get cold air for either side. Find it hard to believe that both would fail at same time. Perhaps that is erroneous.
Many thanks for any input
Thoughts?

boatpimp
11-20-2010, 10:06 PM
TVers,
The above issues have been somewhat resolved.
-The clicking was caused by an aftermarket stereo part (Schoshe) I installed to bypass the Onstar system. The Onstar button had gotten pushed and was trying to work through the aftermarket part. This was also the cause of the battery drain.
-The temp door actuator is ~$115. It seems I need one for each side. Rock auto was more expensive than my local dealer. Shop it around.
If needed I hope this helps someone, I don't wish this on anyone.
-Mark

skeeterbug
11-21-2010, 06:35 PM
I went to the dealer and got this part yesterday (I am not patient), it cost 70 something dollars. I installed it OK but lost the positioning from the old actuator. After the calibration process nothing changed. It was getting dark so I called it a day.

Today I decided to have another go at it. I unmounted it, but left it plugged in and turned the ignition to run to watch it. It goes counter clockwise and back clockwise. Once it reaches the final clockwise position, it just appears to lock up into that. I can turn the controls from vent to the floor and it does not move again. I am guessing the calibration is messed up at this point because it wasn't connected to the HVAC gear while calibrating? I left the actuator disconnected for now, so my vents will at least work. I wrapped the connector in electrical tape to be safe.

Next weekend I will be tackling the blower resistor on the passenger side, as my 1,2, and 3 fan speeds do not work. Perhaps I will give the actuator another attempt then.

skeeterbug
11-26-2010, 05:06 PM
I went to the dealer and got this part yesterday (I am not patient), it cost 70 something dollars. I installed it OK but lost the positioning from the old actuator. After the calibration process nothing changed. It was getting dark so I called it a day.

Today I decided to have another go at it. I unmounted it, but left it plugged in and turned the ignition to run to watch it. It goes counter clockwise and back clockwise. Once it reaches the final clockwise position, it just appears to lock up into that. I can turn the controls from vent to the floor and it does not move again. I am guessing the calibration is messed up at this point because it wasn't connected to the HVAC gear while calibrating? I left the actuator disconnected for now, so my vents will at least work. I wrapped the connector in electrical tape to be safe.

Next weekend I will be tackling the blower resistor on the passenger side, as my 1,2, and 3 fan speeds do not work. Perhaps I will give the actuator another attempt then.

Update: Took the actuator back out and aligned it with the notch on the gear on the car, re-calibrated and it works great!

mmstidham
12-09-2010, 10:33 AM
My vents all work fine in relation to heat/ac but the driver's side vents do not blow out much air if I have the setting on vent/floor. Vent only, I get a little more air from the 2 vents and the floor seems to be good regardless of the setting.

I tried the reset procedure to no avail.

Is it the actuator? I typically run floor and vent whether using heat or ac so could I manually set the actuator and leave it unplugged?

Sorry for the question but I didn't see anyone mention this in the previous 40 pages.

Thanks.

tmr1
12-09-2010, 07:29 PM
Thats what I did with the broken actuator. I removed enough of the bottom dash and air duct to feel the actuator. I then pulled the power plug on that actuator and by using a small coin for a screw driver in the end of the actuator positioned it to the desired position. This has worked for me for several months untill I decide to permantly fix it.

fingam
12-23-2010, 12:29 PM
After trying the reset by pulling the #36 fuse and following instructions, I determined that I needed a new actuator. It came from rockauto.com in a couple of days for a total of $47.09. I then proceeded to remove the old actuator following instuctions that I have read here. I have been unsuccesful at getting the gears to align properly and am beginning to wonder if my control module is bad. I have tried to reset and calibrate it with it uninstalled yet still plugged in so that I can watch it. It appears to find the stops in both directions and finally ends up in a position slightly past 1 oclock. I have included a picture. The picture is just after recalibration process of pulling the #36 fuse, waiting 2 minutes, putting fuse back in and turning ignition on and waiting for 2 more minutes. I then change the control module to floor vent, then bi level, then upper vents and nothing happens at all to the actuator. It does not move. The control module settings appear to have no effect when I switch them. I appear to missing something. PS The dash vents and defrost vents are blowing now with it uninstalled which is better than before anyway. Help appreciated. 2004 Envoy xuv


http://i84.photobucket.com/albums/k40/fingram523/1223101207.jpg

skeeterbug
12-23-2010, 12:34 PM
After trying the reset by pulling the #36 fuse and following instructions, I determined that I needed a new actuator. It came from rockauto.com in a couple of days for a total of $47.09. I then proceeded to remove the old actuator following instuctions that I have read here. I have been unsuccesful at getting the gears to align properly and am beginning to wonder if my control module is bad. I have tried to reset and calibrate it with it uninstalled yet still plugged in so that I can watch it. It appears to find the stops in both directions and finally ends up in a position slightly past 1 oclock. I have included a picture. The picture is just after recalibration process of pulling the #36 fuse, waiting 2 minutes, putting fuse back in and turning ignition on and waiting for 2 more minutes. I then change the control module to floor vent, then bi level, then upper vents and nothing happens at all to the actuator. It does not move. The control module settings appear to have no effect when I switch them. I appear to missing something. PS The dash vents and defrost vents are blowing now with it uninstalled which is better than before anyway. Help appreciated. 2004 Envoy xuv


http://i84.photobucket.com/albums/k40/fingram523/1223101207.jpg

That is the wrong actuator. It is the one in the middle with a big white gear on it. I am guessing you pulled the defrost actuator off instead. There are three of them on the drivers side. Defrost, mode, temp (iirc). The mode is just to the right of defrost if you are looking up at it.

*EDIT* - See you have a V8, mine is the inline 6, not sure if they are different or the same. I am guessing it should still have the big white gear on it though.

fingam
12-23-2010, 12:48 PM
Skeeter, Thanks for your prompt reply. It is the right actuator ... the position of the gears shown in my pic just has the entire white gear hidden behind the box. That is where it stops at just after 1 oclock position. (Sorry, I did not see the reply by quote feature in my response.)

the roadie
12-23-2010, 12:55 PM
...I have tried to reset and calibrate it with it uninstalled yet still plugged in so that I can watch it....That's a problem. When not connected to the flap door that forces the actuator to stop at each end of its excursions (CW and CCW), I believe the control module assumes the shaft or the door is broken, and fails the calibration. Once calibration fails for an actuator, the control module gives up on it and quits sending any position commands.

The actuator has to be physically installed, not just electrically hooked up, to pass the cal.

skeeterbug
12-23-2010, 12:56 PM
Skeeter, Thanks for your prompt reply. It is the right actuator ... the position of the gears shown in my pic just has the entire white gear hidden behind the box. That is where it stops at just after 1 oclock position.

OK. I had the same problem and tried to calibrate it connected but not mounted. It won't work right if you do it that way. The notch on the white gear on the actuator HAS to match up with the notch on the vent door gear. I used my index finger to get a "guesstimate" while the actuator was in position but not screwed in. You can turn the ignition and stop the white gear in a position where you think it will match up with the notch on the vent gear. Don't stress if it isn't perfect, you can move the vent door gear manually until the notches lock in, press and hold the actuator in place and screw it in.

Sorry if my instructions weren't very clear, it is kinda hard to explain.

fingam
12-23-2010, 01:06 PM
That's a problem. When not connected to the flap door that forces the actuator to stop at each end of its excursions (CW and CCW), I believe the control module assumes the shaft or the door is broken, and fails the calibration. Once calibration fails for an actuator, the control module gives up on it and quits sending any position commands.

The actuator has to be physically installed, not just electrically hooked up, to pass the cal.

Roadie, It appears that the flap door is spring loaded to keep the dash vents open when the actuator is removed. What position does the actuator need to be in to install it with the flap door closed. I have tried to stop it around 1 oclock by turning off the ignition at that point and installing it but have not had any luck yet. Is 1:00 the proper position with the flap closed ? And should I keep trying until it appears to line up? Thanks

fingam
12-23-2010, 01:15 PM
OK. I had the same problem and tried to calibrate it connected but not mounted. It won't work right if you do it that way. The notch on the white gear on the actuator HAS to match up with the notch on the vent door gear. I used my index finger to get a "guesstimate" while the actuator was in position but not screwed in. You can turn the ignition and stop the white gear in a position where you think it will match up with the notch on the vent gear. Don't stress if it isn't perfect, you can move the vent door gear manually until the notches lock in, press and hold the actuator in place and screw it in.

Sorry if my instructions weren't very clear, it is kinda hard to explain.

Thanks Skeeterbug, I understand what you are saying and will go and try that. I have not been able to see a notch on the vent gear yet, but I was not looking for one. Here I go!

bromanjr
12-23-2010, 01:22 PM
I did this a few weeks ago (hopefully I am accurate enough to help) and the best position for the gear on the actuator is so that it is sticking out to the right of the actuator (as oriented in your picture) and as it was when it was new. They ship them in the install position on purpose.

The matching gear on the HVAC box will move by hand about 30-45 degrees to change modes and should move freely without the actuator. You can test your modes with the power on at this point and feel the airflow change.

You will need to either disassemble the new actuator (not for the newbe) or connect it and power up the system, then remove plug while the arm is moving and the white arm is facing right and slightly up (2:00 o'clock maybe).

There is a larger tooth on one side, I think it is the HVAC side gear, this larger tooth will easily line up with a larger slot on the actuator side, about mid travel is a good place to start. This can be engaged first and the actuator can then be rotated if needed and positioned on the mounts. then you can gently install the screws and tighten while the two gears stay meshed. Once the actuator is mounted with both screws and the connector installed, the system can be powered up and the actuator will search both ends of travel and the control module will memorize these.

Also: As for this actuator only, There is no difference between I6 and V8 or SWB and LWB or Chevy, GMC or others. The only difference is in the 02s and possibly the 03s there was a different mode actuator and special tool was recommended. My 04 did not have this. this early actuator and special tool has been covered previously in other searchable threads.

My :m2:

fingam
12-23-2010, 05:44 PM
I did this a few weeks ago (hopefully I am accurate enough to help) and the best position for the gear on the actuator is so that it is sticking out to the right of the actuator (as oriented in your picture) and as it was when it was new. They ship them in the install position on purpose.

The matching gear on the HVAC box will move by hand about 30-45 degrees to change modes and should move freely without the actuator. You can test your modes with the power on at this point and feel the airflow change.

You will need to either disassemble the new actuator (not for the newbe) or connect it and power up the system, then remove plug while the arm is moving and the white arm is facing right and slightly up (2:00 o'clock maybe).

There is a larger tooth on one side, I think it is the HVAC side gear, this larger tooth will easily line up with a larger slot on the actuator side, about mid travel is a good place to start. This can be engaged first and the actuator can then be rotated if needed and positioned on the mounts. then you can gently install the screws and tighten while the two gears stay meshed. Once the actuator is mounted with both screws and the connector installed, the system can be powered up and the actuator will search both ends of travel and the control module will memorize these.

Also: As for this actuator only, There is no difference between I6 and V8 or SWB and LWB or Chevy, GMC or others. The only difference is in the 02s and possibly the 03s there was a different mode actuator and special tool was recommended. My 04 did not have this. this early actuator and special tool has been covered previously in other searchable threads.

My :m2:

This worked Bromanjr ... finally but it is not easy by all means. I also removed the gas pedal assembly which made it much easier to get to on my SUV. The 2 o clock position was the trick in my case. I was not sure if I had it aligned properly still but it felt right after following your instructions when I held it in place so I secured it with the screws this time. Re-calibrated it and presto ... I could change modes successfully. This took a while for me but I feel gratified now and it definately saved $$$. This is a great forum and I appreciate all of the prompt responses. All of it was educational and necessary in the process. Again, Thanks to all and Merry Christmas ! PS - I forgot to add that I went to Advance Auto and purchased a mirror w/extention on it and was then able to see the larger tooth ( or elongated projection) that you were referring to on the HVAC side gear. Once I saw that I had a mental picture of what I was trying to align the actuators big white gear with.

dabasham
12-29-2010, 09:47 PM
Okay, so clearly this is a weak spot in these vehicles. I have a 2002 TrailBlazer LT with automatic dual climate control. Everything was working fine until I went out of town with it. 30 minutes down the highway, the heat quit. I could still hear the air blowing, adjust the settings and hear it get louder and quieter, but the air wasn't making it out the vents...any of them. It was trapped somehow. After letting it sit overnight it worked when I got back in it. However, it went out again once I got 30 minutes down the highway. We've done a lot of in town driving, and never had this problem. Only when we were driving longer distances. My mechanic said that it needed some new actuators. One was making the clicking noise, and 2 others were giving fault codes. So, I had 3 actuators replaced (mode actuator, defrost actuator and I can't remember the other one). It seemed to have been fixed, but the other day we went out of town and an hour into our trip it quit again. It just seems weird because it works sometimes and quits others. And again, it is blowing, but just not making it out any of the vents. My mechanic is stumped and it's hard to diagnose because right now it's working. It seems to only quit when it's been driven for a while on the highway. It rarely goes out when driving around town. Sometimes I can turn it off for a few minutes and it'll come back on. Should I replace the remaining actuators and hope for the best? I'd rather not since it's not cheap. PLEASE HELP!!!

nissan56
01-07-2011, 09:13 PM
03Huggy, what prompted you to replace the Actuator? Currently my wifes '02 Envoy makes a clicking sound when you changes modes, like from the upper vents to the lower vents, etc. The air still comes out, but it makes the clicking noise like it is binding as it is changing positions. I didn't know if this is what you were experiencing or not?
Thanks




Do you still have this truck? Mine started the clicking, but it is winter, so I did not have the dash vents on. Now they do not work at all. I guess that is the beginning of the end. Did yours quit working?

Thanks

darndot
01-09-2011, 04:27 PM
I made a small problem into a big problem. I have a 02 TB with a bad actuator. I ordered the part with the little white gear, and thought it would be no big deal. I broke the shaft that the actuator was hooked too.

http://i202.photobucket.com/albums/aa117/darndot/IMG_7378.jpg

Does anybody have the part number for the thingy I just broke?

Thanks for all the help in advance.

the roadie
01-09-2011, 04:35 PM
compnine.com used to post GM part numbers, but that service evaporated. I would go to parts4chevys.com, and give them a call Monday if you can't find it on their web site without the part number.

darndot
01-09-2011, 05:04 PM
I don't even know what to call that part. I will run by the Chevy Dealer tomorrow. I hate to pay full dealer price.

On a side note, I took the actuator part and a gear was stripped. I am assuming that the actuator with the white gear could be used if I pull the gear off.

Thanks Again.

darndot
01-10-2011, 06:25 PM
The GM dealership was happy to order me one. I will snap a picture, and get the part number when it gets here.

ENVOY-SLT
01-11-2011, 01:11 PM
Hey Guys, I have searched high and low on here and can't find anybody with the problem I am having, I have a 2003 Envoy XLT I-6, The heater will not blow out on the Feet Position, all other modes work fine, when I set it to just the feet position the heat comes out the top vents slowly. Any help is much appreciated, this has been like this since I bought the truck, being in New England it would be great to melt the snow off my feat lol...Thanks Again!

the roadie
01-11-2011, 01:21 PM
I don't get it. You're in the right thread, although there are many others.

http://forums.trailvoy.com/showthread.php?t=45175

The "mode actuator" you need to search for discussions of, is shorthand for airflow mode actuator. It specifically diverts air from the FEET to the DASH VENTS.

Recirculate actuator handles recirculation. The defrost actuator handles airflow to the windshield. Driver's and passengers TEMP actuators handle the temperature of the airflow.

That's all there are. Five actuators for five functions. (Two more in the rear of the long wheelbase vehicles for the way back.)

You could also have an obstruction of the airflow door that's deeper inside the ductwork. Pull the driver's side of the lower dash panels and look at the actuator as you command it to different positions and see if its axle moves.

******************************************

darndot
01-23-2011, 05:57 PM
Since I broke the Cam slider thing on the Actuator I had to order the whole thing and take the complete dash out.
For a 02 here is the part number for the whole thing. 89018525
http://i202.photobucket.com/albums/aa117/darndot/IMAG0094.jpg
http://i202.photobucket.com/albums/aa117/darndot/IMAG0095.jpg

You don't want to break the Cam Slider thing. I had about 12 hours, and lots of cussing into replacing it.

Everything is working now, and now my wife is driving in comfort.

aliceaip
02-05-2011, 01:56 PM
Fixed my actuator today , Instruction were great ,I got my actuator from the Electric Connection online 42.00 dollars a/c works like new and saved alot of money from taking to the dealer and getting ripped off.

gotebo11
02-20-2011, 05:20 PM
Is the fuse you are referring to the HVAC B? Some members report success after 2-3 recalibrations, but it's a crap-shoot. Personally, I pull the fuse for 30 seconds, reinsert it, don't touch any control and it doesn't matter if they are on or off, then turn the ignition to run without starting the engine. Just so I can observe the recalibration process for 90 seconds or so. I don't think it matters if the engine's running - it's just important to not touch any control.

If you're curious what's happening, just pull the dash access panels and look at the actuator shafts turning while they recalibrate. Removing the fuse more than once will be required to watch them all, but each recalibration process has its own risk of breaking additional actuators. That's why changing the battery kills a few of them and we keep reading fresh reports of actuator death.

agates1272
03-11-2011, 04:16 PM
Is the fuse you are referring to the HVAC B?

Ya'll want to hear something CRAZY?

I d/c my battery about 7 months ago (as I always do) to clean my throttle body. After putting everything back together, my mode actuator stopped working, and I could no longer get the air to blow through the dash vents. I read these posts, and followed several of the tips to get it to reset, with no luck. I resigned myself to the fact that I was going to have to replace it. I had ordered the part, and had it sitting around, I just hadn't gathered enough patience to try and tackle it.

WELL, I bought a new stereo, and went about the process of installing it, stupidly, without d/c'ing the battery. Somehow, I managed to leave the blower running while testing out the stereo, and killed the battery. I mean, the battery was SO DEAD that I couldn't even get the gear shift to come out of park so i could move the truck close enough to the jump vehicle (I had parked it in the middle of my garage with no room for the other car). I ended up having to use my neighbors jump pack, got the truck started, and LOW AND BEHOLD, I suddenly had air blowing through the dash vents!

I don't know how it happened, but somehow, the actuator finally reset itself, and it is working perfectly now. I don't know if it's a fluke, or if draining the battery like that had something to do with it...but either way it's working now and I can't explain why.

i figured I'd throw this out there, in case there is some kind of correlation between my screw up, and a fix for this problem.

lapaynem4
03-13-2011, 08:34 PM
My hvac actuator for front vents and floor has died on me lately. Tried the reset and had no luck. So taking the advice of some other members, I manually turned it to the vents and disconnected the electrical plug. Bingo... now my vents work. :)

ropie
03-20-2011, 02:20 PM
So I must be completely dumb.... I can't figure out how to remove the lower dash covers. I tried searching but came up empty. Can a guy get some help?

ropie
03-21-2011, 08:33 PM
So I must be completely dumb.... I can't figure out how to remove the lower dash covers. I tried searching but came up empty. Can a guy get some help?

Anyone?? Only pieces I can think of are the black lower piece (that has the odbII connector) and the grey (in my tb at least)piece under the steering wheel.. Any other pieces need to come out?

hingarfi
03-28-2011, 11:40 AM
I have removed (using my home-made special tool) the mode actuator but the white gear is still in place engaged to the flapper valve. I removed the cover from the old actuator and there are missing teeth on one of the white gears. My question -- what next? Do I remove the external white gear from the new actuator and make use of the old white gear which is still engaged to the flapper valve. If so, are there special techniques involved? How to press fit the new actuator to the old white flapper gear? Should I press off the new white flapper gear and use it instead of the old white gear? I believe I read that the flapper valve needs to be in mid-position when installing the new mode actuator. I look forward to reading your experience / wisdom on this hideous experience and I await your help.
TIA
Bert

hingarfi
03-28-2011, 04:16 PM
If you have not messed up the new actuator position, you just press it into the original white flapper gear (rotating white gear as required). Then pull fuse to calibrate. Many previous posts have said this in various ways.

Brubster
03-30-2011, 05:04 PM
Sorry for the "noob reply" but I'm trying to make my way through this whole 43pg thread. I came back to the site to diagnose a problem that I found out was the actuator.

Posted a video of the actuator clicking...
http://www.youtube.com/watch?v=y33T_aDDvVM

As can be seen from the video, the one I am looking to replace is for the rear controls between my front drivers and passenger seats underneath the arm rest.

Do you guys know if the part # is the same for the front and rear actuator?

Thanks in advance guys.

the roadie
03-31-2011, 01:41 AM
Do you guys know if the part # is the same for the front and rear actuator? Very odd failure, but your video made it EASY to see what the problem was. It's an evil GM design where they bundled the actuator in with the ductwork and made it more expensive. It would have been trivial and rational for the design team to take an actuator they already had designed, and re-use it here, but noooooo.....

Anyway, it's GM 15174686, item #26 in the picture. List $137. Parts4chevys.com $91. Never seen one for sale on Ebay but it might be included in consoles you could be lucky enough to find at junkyards.

Brubster
03-31-2011, 02:00 PM
Very odd failure, but your video made it EASY to see what the problem was. It's an evil GM design where they bundled the actuator in with the ductwork and made it more expensive. It would have been trivial and rational for the design team to take an actuator they already had designed, and re-use it here, but noooooo.....

Anyway, it's GM 15174686, item #26 in the picture. List $137. Parts4chevys.com $91. Never seen one for sale on Ebay but it might be included in consoles you could be lucky enough to find at junkyards.

thanks ROADIE! really appreciate it.

CruJones
04-06-2011, 08:56 PM
Newbie here who just found TrailVoy because of this issue I am having with my Envoy. So glad I found this site!

I have a 2002 Envoy SLT that suffered the clicking from the climate control system that eventually stopped, and now I have air only coming out of the floor and defroster vents. After reading through a few pages of this thread, I'm pretty sure I have to replace the HVAC actuator but I need some help.

I want to confirm that I need to purchase the actuator referred to in the GM Bulletin on the first page...

Parts Information
Use This Part Number
89018539
Actuator ASM, Mode Valve

... and can anyone give me a link to where you bought the special HVAC puller tool (assuming I need it for an 02' Envoy w/ climate control)? Unfortunately I don't have the time or tools to make the homemade tool.

I read through quite a few pages of this thread and thought I knew what I needed until I encountered several different part numbers from several different GM Parts web sites, etc. and then I got confused.

Your help is very much appreciated!!!

Me007gold
04-15-2011, 10:08 PM
I have devoleped this same problem. Would removing the center console make this job any easier? I may just crawl under there and move it to where i need it for the time being, then just replace everything once I install my new steering wheel with buttons..

rjames
04-18-2011, 02:35 PM
I have a 2004 chevy trailblazer & I have encountered that same problem as the last two (2) post. Has anyone found the site of the HVAC removal tool? Can someone inform me of the proper channels to find the correct part?

the roadie
04-18-2011, 03:13 PM
Kent Moore GE-47676

http://www.handsontools.com/Kent-Moore-GE-47676-Module-Puller-----_p_40315.html

http://www.handsontools.com/assets/images/ge-47676.jpg

And pictures of home built ones have been posted here. The Kent Moore ones have been selling on Ebay for $40-50

bromanjr
04-18-2011, 03:28 PM
I have a 2004 chevy trailblazer & I have encountered that same problem as the last two (2) post. Has anyone found the site of the HVAC removal tool? Can someone inform me of the proper channels to find the correct part?

My 2004 Envoy did not require the tool for replacement, they re-designed the actuator in '03 or '04 so you should not need it.

Just get the right part. The one mentioned above is for an '02, not the same as the one you need, the one you need comes with the white plastic arm already attached.

My :m2:

CruJones
04-23-2011, 11:52 PM
Today I replaced the HVAC Mode Door Actuator, the Bose stereo head unit and the climate control head unit. The easiest part of the whole day was the HVAC Mode Door Actuator (good news for those looking in this thread for help replacing theirs). The only reason the others were harder was because I had to take out the center console to get the front bezel off (but that's for another thread).

The instructions in the first post are fantastic and there is a ton of good info in the subsequent posts. I wanted to add a few notes that hopefully will help the next guy.

First, I ended up buying a Kent-Moore GE-47676 HVAC Mode Door Actuator Puller tool on eBay for $50 (see pictures). In my opinion, a worthwhile investment. Now that I've done it once, I can see how others have had success in prying the actuator off with screwdrivers. I'm glad I bought the tool because you're working in such tight quarters, in such an awkward position, that the puller just makes it so much easier to get the pressed acuator off. *Note, I have a 2002 Envoy so the tool (or prying screwdrivers) is required to get the actuator off. All subsequent years are lucky they don't have to deal with this.

Second, make sure you have the proper tools before you start. I did not have a low profile ratchet set so I fought a little bit getting the screw out that is directly behind the metal bar. There's just not enough room for the socket and ratchet to fit in that area. Luckily for me the factory did not tighten the screw so tight that I couldn't get it off by turning the socket by hand (it hurt, but it worked). Somewhere in the first 20 pages in the thread someone posted a picture of a good ratchet set to have to get this screw off. I recommend picking one up before starting.

Third, I was a little unsure of which actuator I needed to replace. There are three actuators on the drivers side. The one I replaced is the one in the middle, that sticks out a little farther than the other two. It has "HT" in green in the part number. I guess I was unsure because the new one had "MT" in the part number but the place I bought it from assured me it was the correct actuator. Maybe an improved part? Once I got the broken actuator off, I found that it was set in a different position than the new one I purchased. Some people in this thread have suggested manually turning it with a screwdriver or similar tool. I would not recommend doing that because you run the risk of stripping the gears if they don't readily turn. Instead I took the advice of someone in this thread and connected the wiring harness to the new actuator, turned the key to the on position, let the climate control do it's thing for 2-3 minutes without touching it, and then changed the mode so that the position ended up in the same position as the broken one I just removed. I then turned off the car, disconnected the battery again and reinstalled the actuator. I reconnected the battery, set the key to on, waited 2-3 minutes while it calibrated and I was back in business. Climate control works like a charm now from all vents.

For my 2002 Envoy I purchased the actuator from www.oehq.com and it was part number ACD15-73044 "Mode Valve Actuator" for $36.58. I posted a pic of my old actuator because the original post is for a newer year I believe that has a white plastic piece coming out of it. The one for the 2002 doesn't.

Thanks so much to the OP and all posters in this thread for helping me out with your great instructions/advice.

socaldooley
05-01-2011, 11:34 AM
A big thanks to everyone who posted on this thread. I had a similar issue where my air would only come out through the floor. Not good for hot days at all.

After numerous tries to reset it, I decided to change out the actuator. The step-by-steps and pictures were very helpful, but so were the numerous posts on people's experiences with the fix.

Thanks to everyone, I fixed the problem myself and now have cold air blowing from the proper vents. :)

Me007gold
05-19-2011, 03:20 PM
replaced my actuator today, now I have the opposite problem. The A/C is coming out of the dash vents just fine, however It will not go to the floor, and when I turn the selector to defrost it comes out of both the dash vents and the defroster. Do I not have it lined up correctly? or is it possible the other actuator suddently went bad? I am at a loss.


*edit* damn I feel stupid. I didnt have the actuator screwed in completly

noto777
05-24-2011, 06:55 AM
I have a 2006 Envoy Denali that is experiencing this problem with no air out the dash vents. I too replaced the battery about a month ago. Took it to the dealer and was quoted $800, dash must be disassembled, yada yada. I've read about the special tool that lets them do this much faster. Does this tool work on my car or is it for older Envoys only? I tried pulling the B fuse to see if it would recalibrate but that didnt work. I'm contemplating doing it myself and have read through most of these posts but I'm not sure they apply to my exact model. Has anyone done this on a 2006 Denali?

bromanjr
05-24-2011, 09:34 AM
The special tool only applies to the 2002 models, and the Actuator is a different part # also. For 2003 and up they are all the same for the mode actuator. I replaced mine and if you follow the how-to earlier in the thread you will be fine.

Just keep in mind, the new actuator is shipped in a neutral position and you manually move the arm on the door (part of the HVAC in the truck) to engage the two as you install. Do not plug in and apply power until you have the new actuator fully installed.

redbird00
05-29-2011, 04:24 PM
finally fixed mine today. it was a piece of cake once, i figured out what i was looking at. my socket set supposedly came with a 5.5mm socket, the place holder was labeled 5.5mm but it actually came with a 6 and 12 point 6mm socket. the 6 point socket worked fine though. and the electrical tape idea was genius for the one closer to the steering wheel.

noto777
05-31-2011, 10:04 PM
Getting ready to try this on my 2006 Envoy Denali. Had a couple questions. I took a picture of the actuators I could see after removing the cover under the dash. The picture of the actuator is the one right above the gas pedal. Is that the correct one? The other photo is of my new actuator. That is the position the white piece was in when I received it. Is that the correct position to install it or do I need to move it. If so, How do I move it? It doesnt seem to want to turn very easily.

bromanjr
06-01-2011, 12:38 PM
Getting ready to try this on my 2006 Envoy Denali. Had a couple questions. I took a picture of the actuators I could see after removing the cover under the dash. The picture of the actuator is the one right above the gas pedal. Is that the correct one? The other photo is of my new actuator. That is the position the white piece was in when I received it. Is that the correct position to install it or do I need to move it. If so, How do I move it? It doesnt seem to want to turn very easily.

The shipped position is the easiest to install. The mating gear on the shaft will move and line up with the new actuator, make sure it is bolted down before you connect and apply power. When I did mine, the door/shaft/gear in the vehicle would move easily and stay in the position it needed to be, I lined up the gears then positioned the actuator down into its mount and then installed the screws.

noto777
06-03-2011, 03:58 PM
Well I'm struggling getting this part out on my 2006 envoy. I dont think I'm going to be able to get to it without removing the gas petal. Is that just three bolts? Is it easy to put back on?

TrailingJack
06-23-2011, 06:06 PM
Just found this forum and I'm sure glad I did.
Same problem as everybody else.
Replaced the battery over the winter, warm weather arrives and the dash vents don't work...
I tried the fuse reset with no luck, so I'm going to attempt to replace the actuator with instructions from here.

Here's my question...having read through the bulk of this thread, I didn't see any mention of anyone perfoming this fix on a Saab 97-X. I have an '06 and I wondered if removing the dash panels or gaining access to the part are any harder or easier?

Any help would be appreciated.

I think I'll be spending some time on this forum to fix the many other problems this car has.
Thanks to all in advance...

bromanjr
06-23-2011, 06:32 PM
Just found this forum and I'm sure glad I did.
Same problem as everybody else.
Replaced the battery over the winter, warm weather arrives and the dash vents don't work...
I tried the fuse reset with no luck, so I'm going to attempt to replace the actuator with instructions from here.

Here's my question...having read through the bulk of this thread, I didn't see any mention of anyone perfoming this fix on a Saab 97-X. I have an '06 and I wondered if removing the dash panels or gaining access to the part are any harder or easier?

Any help would be appreciated.

I think I'll be spending some time on this forum to fix the many other problems this car has.
Thanks to all in advance...

Don't think the actual HVAC box is different, actuators and all, but get the right part number from a dealer just in case. The trim panels may vary slightly but the process should be identical.

TrailingJack
06-23-2011, 06:38 PM
Don't think the actual HVAC box is different, actuators and all, but get the right part number from a dealer just in case. The trim panels may vary slightly but the process should be identical.

Thanks. I believe the part number I got was right (89018675).
I'm really not sure how the trim comes off but I'll tackle it when the part shows up.
Amazon for $43.87.
I guess we'll see...

TrailingJack
06-30-2011, 04:14 PM
Ok here's the deal...
'06 Saab 97x.
As I posted before, no dash vents working after replacing battery.

Here's my actuators:

http://i126.photobucket.com/albums/p115/TrailingJack/100_2438.jpg

This picture was taken laying on my back, upside down.
There only seems to be 2 actuators.
The one on the bottom of the picture is towards the front of the vehicle and is sitting lower if you were to look at it from the side, right side up.
The other one is what I think is the door mode actuator (which I bought and I think needs replaced). It has numbers on the side beginning with "HL", just like the new one. The other one starts with "S"-something.
I thought I would try the fuse reset to see them move, and the "S" actuator did but the "HL" did nothing.
Is this a sign of a bigger problem, or should I figure on changing it out anyway?

TrailingJack
06-30-2011, 05:12 PM
Got impatient and went ahead and removed the old one.

The white gear was turned to the far right (the left side of the gear is actually parallel to the bottom of the black plastic housing).
The metal hole with the notches is in the 1 o'clock position.
My new one has the gear and the notches both in that postion.

Also, I touched the toothed gear on the vent door and it seems to be spring loaded.
It flipped to the opposite position when I touched it and stayed there.
How do I line up the new one?
I don't want to change anything on the new one and screw it up.

Thanks in advance for any insight.

TrailingJack
06-30-2011, 06:18 PM
Continued to be impatient and went ahead and mounted the new one up.
Wasn't sure if the white gear was going to line up but it seemed to.
Reinstalled the screws (WOW!!!), plugged it in, turned the key and watched it work.
Let it alone for a minute or so then started up the car, tried the controls.
VOILA!! It worked!

Thanks so much for this forum.
I'm not particularly handy and this was a bear but I couldn't have done it without the knowledge here.

Tried to send a pm to a member to have him look at my posts while I was working on it but they didn't seem to send.
If they did, ignore them now (you know who you are!).

Thanks again.
Great site!

indyjps
07-01-2011, 08:14 PM
Got it done, everything works.

Not much new to add except the plastic dash piece infront of metal bracket can be cut out of the way if desired and bolted back in place. I broke mine flexing it to replace door blend actuator while I was in there. For mode door its not necessary but frees up a lot of room.

halley123
07-09-2011, 05:12 PM
hi i got a 2002 trailblazer i replaced the mode actuator due to no air coming out dash vents. all i get are floor and defrost. ive recalibrated it and i can hear and feel the mode actuator calibrating, but it seems like the only actuator actually moving after the recalibration (removing hvac b fuse) is the defrost one. i shift from dash to defrost the defrost actuator moves but the mode one does not. yet it moves during calibration but not for actual use. could it be the climate control or wiring?

the roadie
07-09-2011, 05:42 PM
If it's not on the shaft properly, it could be moving during calibration, but silently failing the calibration if the control module doesn't see reasonable performance. Or the control module or the wiring could have a problem. I'd see if you can find another member to swap control modules with - a good reason to make local friends in the regional forums or at meets. Otherwise with the schematic that's been posted, you can look

Or look at the voltages at the actuator during the calibration and see if the position feedback sensor (potentiometer) is sending back accurate position data.

A dealer or an independent mechanic with a high end scan tool can take control of the actuator and command it to go through its paces if you're not up for detailed electrical troubleshooting like that. Sometimes repairs are just beyond the DIY threshold.

TB_n00b
07-12-2011, 10:20 AM
Finally fixed mine this past Sunday. Took about an hour. Hardest part was figuring out how to verify the module and vent gear were properly aligned. Got it together and enjoyed the wonderful front vent air flow that I have missed for over a year. AC is not as effective when it's blasting out of the defroster.

I pulled open the old module. Couldn't find anything wrong with it. I guess something went with the motor or the circuit board cause the gearing all looked perfect.

Steve Bell
07-12-2011, 08:45 PM
I can't seem to get the actuator arm lined up with the door. I have tried multiple positions as listed is this thead with no luck. After I reinstall the fuse and turn the key to the on position the actuator moves a bit from the 1 O' Clock position to about the 2 O'Clock position and stops and then does nothing.
Can anyone help?

Steve Bell
07-15-2011, 01:37 PM
I can't seem to get the actuator arm lined up with the door. I have tried multiple positions as listed is this thead with no luck. After I reinstall the fuse and turn the key to the on position the actuator moves a bit from the 1 O' Clock position to about the 2 O'Clock position and stops and then does nothing.
Can anyone help?

Guess not, nevermind. I actually had a bad actuator and returned it and the new one works perfect.

holowko
08-03-2011, 10:46 PM
thanks for the great pics and info. Got to do mine this weak.:eek::eek::eek::eek::eek::eek::eek::eek::eek: :eek::thx

Roamingdoc
08-06-2011, 08:45 PM
Amazing, what a site... I love this thread. I think mine started acting up about two years ago and Roadie and Ray gave me advice. "But" strangely over a few days the problem (driver vent only blows hot, while the pass side blows the correct COLD A/C air - no issues with dash vs. floor but still warm air on driver side and cold air on passenger side) WENT away - But AS I understood this meant the DRIVER'S TEMP ACTUATOR was the problem... ?? Right.

Okay, as I've never really had to take it out and am NOW revisiting (yup, disconnect battery and voila it did it again! Hot on driver side, cold on passenger side) DOES THE DRIVER'S TEMP ACTUATOR "also" require a special tool to remove in '02 or was that only for the Floor/Dash Vent Mode Actuator?

Many thanks for such a great thread and, as always, remarkable site. GM mechanics should TRAIN here!

rosemclark
08-09-2011, 10:42 AM
just wondering about your post - when you state the dash vents arent working - did you still hear the ac blowing in the dash and the vents were open or closed. I can hear the ac blowing and if i switch to floor or defod they blow correctly but when it is set to blow in the cabin - no luck it is just blowing inside the dash. and the back set it blowing correctly for all settings...:confused:

Me007gold
08-09-2011, 10:47 AM
just wondering about your post - when you state the dash vents arent working - did you still hear the ac blowing in the dash and the vents were open or closed. I can hear the ac blowing and if i switch to floor or defod they blow correctly but when it is set to blow in the cabin - no luck it is just blowing inside the dash. and the back set it blowing correctly for all settings...:confused:

Yep. Thats how it is. Your mode actuator is done.

rosemclark
08-09-2011, 11:06 AM
Yep. Thats how it is. Your mode actuator is done.

dang it.:hissy:

Roamingdoc
08-10-2011, 09:34 AM
Ouch
Well there are many more experienced "car" folks here than me (Roadie and Ray and others) but that sounds VERY astronomical to me. I have had to replace those (both) on my wife's '02 Tblzr but went to a trusted local mechanic. Don't recall paying even 1/3 of that total for all of it... and my mechanic isn't inexpensive. We have had no issues since then with "that" stuff but the Tblzr line seems to blow hot and cold. Get a good one, great. Get one that was put together by left handed line people and it is terrible. We had such or have such and Chevy did not do much when things like the 'transmission' failed with low mileage but out of warranty... wish you good luck with your efforts.

Roamingdoc
08-10-2011, 10:08 AM
If it's not on the shaft properly, it could be moving during calibration, but silently failing the calibration if the control module doesn't see reasonable performance. Or the control module or the wiring could have a problem. I'd see if you can find another member to swap control modules with - a good reason to make local friends in the regional forums or at meets. Otherwise with the schematic that's been posted, you can look

Roadie, while I contemplated doing this job the 'problem' once again (last year too) WENT away on its own. I have followed all these threads and have the great diagrams and just WONDERED how it fixes itself? We had that 'driver' side hot air while 'passenger side' COLD air thing going on (driver's temp actuator) and, given that it did such early last year after a battery disconnect, I was contemplating pulling it off but less than 72 hours later is is working. Any thoughts on why or 'if' I should just pull it (rather not but then again wonder how long the good stuff will happen). Thanks.

RSK
08-11-2011, 05:54 PM
Hey everyone

It's been a while since I posted last but I was having problems with the passenger side actuator not working. The dealer said the actuator was not working properly and quoted me around $900 to get it fixed. I decided AC was a luxury for me and didn't get it fixed

About a month ago It was about 100 degrees and I was wishing I had AC at that moment so I decided to turn it on. It worked! I don't have a reason why and am thankful. I haven't had any problems with it since.

thanks for help with it

Roamingdoc
08-11-2011, 07:34 PM
RSK - YUP, exactly what happened to me. Roadie is the King of HVAC and I was hoping he's weigh in on 'what might' be happening such that it stops working (and this thread explains well why that occurs) BUT then suddenly springs back into life with no attention. It would be nice if we could count on 'that' happening whenever, but I kind of doubt it. Glad yours is up and running.

the roadie
08-11-2011, 08:38 PM
Nobody could tell why a circuit quits working, then spontaneously recovers. The evidence is probably gone.

Sometimes, I've heard of a recalibration succeeding after a failure, for instance if the owner disconnects their battery again for another project. But if the actuator dies with a broken gear tooth, that's not likely.

Roamingdoc
08-11-2011, 08:57 PM
Thanks Roadie... if I take it out I'll send it to you for a "Vulcan mind probe" and then we will know for sure! ;^)

racer383s
08-13-2011, 08:39 PM
Looks like same old story I've seen too many times on here.....Disconnected & reconnected battery....... then only have air from floor & defrost outlets.....try to reset/recalibrate with no results..... buy and install new actuator & now only have air coming from dash outlets, if you turn control to defrost, some air comes out there but most continues to come through dash outlets....I've tried to reset/calibrate new actuator and it doesn't change anything.... I don't understand how a working part just fails from having the battery disconnected and reconnected????

the roadie
08-14-2011, 10:55 AM
I don't understand how a working part just fails from having the battery disconnected and reconnected????GM design error - they fail during the recalibration process when the HVAC control module loses its memory from having the power off. They slam into the mechanical stops trying to rediscover the end points of the travel.

Roamingdoc
08-15-2011, 11:36 AM
MY new procedure...
As this recently happened when I 'removed' the neg term from battery connection to "remove radio" from dash (sending to replacement radios for a new CD player/fix but keeping 'same' radio and computer program within that) I AM now JUST going to remove the radio fuse and leave the battery hooked up.

I have lots of play in the behind radio wiring and can reconnect with futzing about so hopefully we won't short anything (which is why as I understand it we disconnect the neg ground)... hoping to keep the actuators working through it all.

Take care.

racer383s
08-19-2011, 01:21 PM
When I installed the new actuator, I was getting the same result as Steve in post 455.... I'm wondering if my answer is in post 456 (new actuator was bad) ???


GM design error - they fail during the recalibration process when the HVAC control module loses its memory from having the power off. They slam into the mechanical stops trying to rediscover the end points of the travel. Would this be a design error for the actuator or the or the control module?

the roadie
08-19-2011, 01:39 PM
Would this be a design error for the actuator or the or the control module?It's a shared problem because the SYSTEMS designer should have anticipated the interaction of the actuator hardware and the algorithm programmed into the control module for recalibration. It would have been SO SIMPLE to change about ten lines of code to avoid the issue. I do very similar things every week in my day job to make sure that the software recalibration does no harm to the hardware we're using in our semiconductor test systems.

I've actually published what I call Carton's Three Laws of ATE Systems, with apologies to Isaac Asimov's Three Laws of Robotics. (ATE stands for Automatic Test Systems, million-dollar systems to test all sorts of chips)

1) The ATE system shall not harm, or through inaction allow to come to harm, a human being.

2) The ATE system shall obey all commands given it by a human unless following such commands will violate Law #1.

3) The ATE system will protect its own existence unless such preservation will conflict with Laws #1 and #2.

Scappy
08-19-2011, 10:50 PM
Anyone interested in selling their puller ? My actuator needs replacing on my 02 Envoy as it has been clicking and no air to front vents when selected on switch.

racer383s
08-21-2011, 09:52 AM
It's a shared problem

I was sorta hoping that the problem was in the actuator and that the replacement part would have been redesigned to the eliminate this issue in the fututre..... I don't look forward to this every time the battery is disconnected... :hopeless

RedEnvoyDenali
08-22-2011, 06:45 PM
I was sorta hoping that the problem was in the actuator and that the replacement part would have been redesigned to the eliminate this issue in the fututre..... I don't look forward to this every time the battery is disconnected... :hopeless

They must be making the replacement units better than the originals because when mine was disconnected bang went the actuator, the replacement has been through a few disconnects with no problems.

:thumbsup:

Ray Dockrey
08-23-2011, 12:34 PM
Anyone interested in selling their puller ? My actuator needs replacing on my 02 Envoy as it has been clicking and no air to front vents when selected on switch.I just looked and there are a couple on E-bay but man are they expensive. I was able to wiggle mine off the shaft but others have tried that and broke the shaft.

Nakattk
08-28-2011, 09:39 PM
Is this the right part to get if your air stops coming from the front dashboard vents on an 05 trailblazer? There are too many different ones I am confused.
I tried to get it to recalibrate but looks like I will have to replace it.

http://www.amazon.com/ACDelco-15-73596-Actuator-Assembly/dp/B0016IDV9M/ref=sr_1_1?s=automotive&ie=UTF8&qid=1314581817&sr=1-1
I think this one might be better if it is the right one?
http://www.dormanproducts.com/p-45589-604-110.aspx?year=2005&make=CHEVROLET TRUCK&model=TRAILBLAZER: LS&engine=L6 - 4.2L (256 CID): GAS: FI: N: S&parttypeid=40&parttype=Air Door Actuator&skinid=1

Me007gold
08-28-2011, 09:52 PM
Is this the right part to get if your air stops coming from the front dashboard vents on an 05 trailblazer? There are too many different ones I am confused.
I tried to get it to recalibrate but looks like I will have to replace it.

http://www.amazon.com/ACDelco-15-73596-Actuator-Assembly/dp/B0016IDV9M/ref=sr_1_1?s=automotive&ie=UTF8&qid=1314581817&sr=1-1



Product Description
ACTUATOR,MODE VLV


looks like it to me.

Nakattk
08-29-2011, 10:05 PM
I asked the dealership how much it would cost to replace the mode acuator for the front vents. They knew exactly what I was talking about like they do it everyday. It would be $380 labor and $80 for the part. :no: They made a big deal about it and how hard it is to get the alignement right. Is it really THAT hard? Is it worth the cash they want to do it?

troy11556
08-29-2011, 10:09 PM
I asked the dealership how much it would cost to replace the mode acuator for the front vents. They knew exactly what I was talking about like they do it everyday. It would be $380 labor and $80 for the part. :no: They made a big deal about it and how hard it is to get the alignement right. Is it really THAT hard? Is it worth the cash they want to do it?

you can do it yourself and its a great deal cheaper. The alignment is not that bad to do the actuator is a fairly common problem and they tend to fail especially if your battery is dead or you replace the batter, their not to hard to do.

Nakattk
08-29-2011, 10:19 PM
Thanks for that, it make me feel a little better about it. I am going to order the one from amazon. did not want to get another AC Delco one but it will be the quickest one to get here.

gmtrailblazer
08-30-2011, 09:50 PM
Got battery replaced, now vents don't work, only feet and defroster. Already tried the fuse, didn't fix it. For the actuator, is this the correct part?



http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_AIR-DOOR-ACTUATOR-Dorman---OE-Solutions_10096878-P_2102_R%7CGRPCOOLAMS_1740352588____

Me007gold
08-30-2011, 09:55 PM
Got battery replaced, now vents don't work, only feet and defroster. Already tried the fuse, didn't fix it. For the actuator, is this the correct part?



http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_AIR-DOOR-ACTUATOR-Dorman---OE-Solutions_10096878-P_2102_R%7CGRPCOOLAMS_1740352588____

Controls A/C Blend Door; Temperature; Main Unit; wo/Bottom Cover; Dorman - OE Solutions

No you need this one

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_AIR-DOOR-ACTUATOR-Dorman---OE-Solutions_10096432-P_2102_R|GRPCOOLAMS_1740354143___

Controls A/C Blend Door; Mode; Main Unit; Dorman - OE Solutions

Roni
09-15-2011, 01:56 PM
I'm new to the site. My wife has a 2004 TB. I had to replace the battery, because it went out on me. Now the AC only blows out the floor and defroster. I took the mode actuator off and when it tries to calibrate it will go until the gear hits the stop, but the actuator shaft keeps on going for about 15 sec. then stops. I now have a new part#89018675. What I'm trying to find out is where the switch on the dash needs to be set and where the air door needs to be when I put the new part on, and also should I pull fuse HVAC 36 before I plug in the new actuator? Is there anyone that can help with some info.?
Mike

nospark
09-20-2011, 10:19 PM
I just changed my damper control motor and allowed resting by pulling fuse 36. It's been bad for 3 yrs., great dash air, switches to def. when pushing def. button. and it blow some on other settings as there selected. What I don't remember after 3 yrs. is does it always blow out dash some when other modes are selected? I have read allot of the threads on this but can't find this answer.
Allot of great info. here, Thanks:thxhttp://forums.trailvoy.com/images/smilies/thx.gif

mudgie
09-21-2011, 06:18 PM
After two years of having mine manually set to "Vent" I finally got around to ordering the actuator and installing it. What a pain! It seemed to be working great but I soon realized that it would start on vent and switch to floor after a few minutes. I did the fuse thing and all is well. Thanks all!

innkeprgayle
09-21-2011, 09:47 PM
Just joined the site today. Not because I want to become a mechanic but because I want to know what is going on. It feels like every time I get some work done on my trailblazer, the result of that work makes something else go bad! I recently had the back door of my 03 trailblazer replaced (an anonymous giver left a large dent to the tune of $2200 repair) by my trusted mechanic who found a replacement at a very reasonable price. At the same time, I had my battery replaced. My keyless remote stopped working (locking and unlocking but the auto start still worked) and the air conditioner blower no longer works on 1,2,3 and blows like crazy on 4. Because I had both repairs done, I wasn't sure if replacing the back door had anything to do with the key remote but I was pretty sure it probably didn't have anything to do with the air conditioning. Through another online forum, I was able to fix the problem with my key remote (simply disconnected the battery overnight and reconnected in the morning...all works fine now). But the air conditioner and just the overall blower does not work correct. I am hoping it will correct itself but am afraid to let the blower go full blast for fear of blowing out the motor. (mentioned by someone else on the forum). "The Roadie" is right on :thumbsup: about the interaction of alot of functions on the algorithm programmed into the control module. Knowing that it is GM's flaw doesn't make me feel better but at least I feel I have a better grasp on the WHY? Thanks for all the great information.

Benny75
10-03-2011, 08:22 PM
Just joined the site. Great interaction here. I had been a lurker for years. Well long story short my 02 Envoy is no longer with us and I have a new mode door actuator that I no longer need. It is in the marketplace under interior. I listed it in Sept.with no interest. It is still there with a make me an offer. Not looking to get rich I really just want to see it used as I have no need for it.
Ben
(Sorry for the self promotion just trying to help somebody out.)

twins
10-03-2011, 09:00 PM
Just joined the site. Great interaction here. I had been a lurker for years. Well long story short my 02 Envoy is no longer with us and I have a new mode door actuator that I no longer need. It is in the marketplace under interior. I listed it in Sept.with no interest. It is still there with a make me an offer. Not looking to get rich I really just want to see it used as I have no need for it.
Ben
(Sorry for the self promotion just trying to help somebody out.)

How much u want for the actuator, what is the part number? Thanks

the roadie
10-03-2011, 09:43 PM
Please....classifieds. Reduce thread pollution.

prodigy467
10-09-2011, 06:02 PM
First of all thank you for taking the time to write out this guide, it was very helpful.

I had the same problems as others and eventually I couldn't get the air to blow through the upper vents. I followed this guide to replace the actuator and after it was changed I also pull fuse 36 and let the system reset. Now the vents seem to be stuck on on the upper vents and won't really blow through the bottom, they are also not totally shutting off when I have defrost on. When the system goes through its setup after the power has been pulled, it seems like it goes through a phase where it would be on your feet, but after its done, it doesn't blow through the lower vents

As far as the instructions are concerned, when it came to this step:
"You will need to adjust the white gear shown in pic #46 to be at the same location as the gear on the actuator you removed in order for it to go back in correctly"
I took the cover off my new actuator, removed a gear, set the main gear to the same position as my old one, then replaced the gear and cover. Is this the right way to adjust these things?

Anyone have ideas what might be wrong?

racer383s
10-13-2011, 08:45 AM
It's possible that your new actuator is faulty.... I had a faulty new one and there was a post in this threead where another member had a new one that was faulty... I picked up one from NAPA on a Sat because thay were the only place who had one at the time.... I spent several hours trying to make it work, then had a freind of mine at a shop try installing it and he hooked his Modis scanner up and it would work 1-2 times, then fail... Got a new actuator from local Chevy dealer and it worked correctly...

tmbucz
11-03-2011, 08:20 PM
After thoroughly reading the thread i assume i am also a victim of door mode actuator failure after battery replacement. The floor and defrost work but vents do not. Tried the recalibrate process with fuse removal and got heat to work again from floor and defrost with only a trickle of air from vents. (yes heard the actuator trying to do it's thing - but more of a thumping than a clicking noise...) I have not seen anyone talk about replacement on a 2007 Envoy with auto dual climate control. Anyone aware of problems accessing and replacing the actuator? (do i need the tool?) I've seen the thread with photos but that is a '03 TB i believe.

EDIT: Since I've re-calibrated the air temp fluctuates between hot to cold. i can only get it hot by getting out of Auto and going manual and cranking it to 85+. Might the Driver temp actuator also need replacement maybe failing at same time the door actuator broke should replacing the door actuator fix both the no vent and stable air issues?

Earlier posts show a parts locator and store no longer open - so where is best, least expensive and most accurate place to find the correct part number & $$.

thanks for the help in advance - this is a great forum!!

mac02ltz
11-16-2011, 03:42 AM
Read just about every post here and seen a couple with a similar issue who's questions were never really answered. My vent all blow out air no matter if it's, floor, dash, or defrost. However only the passenger and rear blow out HOT air.. if I switch it to AC it will blow out cold air. Driver blows cold no matter what. Am I to assume this is the Driver's side temp actuator? I will try a reset later today during the day, but having cold air blowing in my face in Indiana isn't present lol.. I have to completely close off my drivers side vents. Also this has the full climate control system in it being the 2002 LTZ.

Also I noticed a little bit ago that my blower actually sounds a tad bit muffled.. I will check it out tomorrow as well to look for obstructions but has anyone else heard of this before?

herc2000
12-06-2011, 06:55 PM
Hey guys, reading your posts, I've been getting lots of my parts from rockauto.com, almost always have the cheapest prices, this part here goes for as low as $33 there.:eek:

sweeneyh
01-14-2012, 12:04 PM
Hey guys I have only been a member for less than an hour. But I have already found an answer to the problem that I am having. Not only did I find out what the was causing the problem but also how to fix it. Thanks to 03Huggy and his post on the mode actuator I will be able to make the repairs and have a happy wife again. That to me is a double plus. I will let you guys know how the repair goes.:D

Outlaw_99
01-19-2012, 12:08 PM
I cant quite find the exact same issue we have (I may be missing it) but my A/C on driver side blows hot air while the other side blows cold... Every now and then it will blow cold and I have had the three loud "clicks" since we bought it in `09...

Is this the same issue as this thread fixes? Mine is the 02 LTZ with split controls...

TrailblazrI6
01-19-2012, 12:37 PM
I cant quite find the exact same issue we have (I may be missing it) but my A/C on driver side blows hot air while the other side blows cold... Every now and then it will blow cold and I have had the three loud "clicks" since we bought it in `09...

Is this the same issue as this thread fixes? Mine is the 02 LTZ with split controls...

Yes. There are 2 temperature actuators - 1 for the drivers side, 1 for passenger. Whichever zone isnt changing temperature, is the one with the bad actuator.

TAP119
01-22-2012, 09:21 PM
Thank you all for the great information, but I will have to pay to have the blend door actuator replaced. I tore the center dash and driver's dash apart in Envoy in my mother-in-law's garage this afternoon. I live in a row home in Philly, so there's nowhere to work on my car out of the weather.

After dismantling as much as I could, I could barely see the middle actuator, let alone remove it. This was while lying on my back on the floor of the driver's side looking up inside the dash. I can work by feel, and I have but I concluded that I am out of my league on this one. This repair is beyond my skill set and I'm not as flexible as I once was.

So, thank you all once again and I will cry about the labor costs another time.:(

pump
02-14-2012, 06:26 PM
I had the mode actuator problem after disconnecting the battery to do some work. Probably screwed it up by fiddling with the AC controls right after turning on the ignition??? It stopped in the floor only position. Followed the instructions contained in this thread and HVAC controls/system air flow works as it should. A finger drive (1/4" square & hex) or a finger ratchet drive helps a bunch on the R&R.
I took the old actuator apart to see what was wrong. I found that it was still functional (nothing broken) but I could not get the solid state logic swith to reverse the DC power to the drive motor, therefore it would not reverse the rotation. Either the feedback potentiometer is bad or the logic switch failed.
Great forum:tiphat
Anyone in the Plano Texas area that needs help on this one, send me A PM to arrange contact and I'll be glad to help out.