Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner

How to: Replace blower resistor pack replacement WITH PICS!

Tags
how to
771K views 755 replies 423 participants last post by  tblsfan 
#1 · (Edited by Moderator)
I had a shot blower resistor pack (no 1,2 or 3 speeds on the blower) so I ordered a replacement unit. It arrived today and I put it in just now. I looked around and did not see a "how to" on it, so maybe this will help some others.

Vehicle 2002 Trailblazer LS - no automatic temp controls

Time spent: about 20 minutes (spent time getting the right stuff from the garage :) ).

Part: blower motor resistor (I used parts4chevys.com so I used the drill down menu to find it, sorry I do not have the PN handy)

Tools:
7mm socket or nut driver
7/32" socket or nut driver
one long screw driver (flat blade) - optional
flash light - optional



step one: locate the two 7mm screws holding the plastic kick plate under the passenger side dash, remove them, and then carefully remove the plastic cover



step 2: look up under there and you can see the old resistor pack. It has one connector and a pair of wires going from it. Unscrew the two 7/32" screws and it will come down, unclip the wire harness



step 3: open the glovebox and empty it, now release the catch so that it can hang down



step 4: locate the end of the wires that came from the resistor pack, they are plugged into the blower, release the clip and remove them (I used a screw driver to push in on the little clip to release it)



step 5: reverse the process and install the new one :)

here is the comparison of the two




hope that helps somebody....

From the Roadie: Since everybody looks in this post if they use a search, I'm just going to add the schematic HERE for one-stop shopping
 

Attachments

  • 73.5 KB Views: 109,363
See less See more
7
#504 ·
Thanks for the info and pics for the replacement of the resistor pack. I had lost 1-3 fan speeds and was getting ready to pay a service shop to diagnose and repair the problem. Went to Auto Zone and bought a new resistor for $28.00 and with the pics to go by only took about 15 min to change it out which corrected the problem. The replacement resistor was a Duralast DR 755.
:tiphat :woohoo:
 
#505 ·
HELP It's hot down here

I had the same problems with my blower, one speed worked. I disconnected my battery and replaced the blower motor resistor and fan speeds work fine. My problem now, is that only the floor vent works. I called the dealership and they won't give me a straight answer or any advice without paying them a $100 "Diagnostic Fee" Please help!!! I'm pretty handy around a vehicle but this ones got me stumped>

Thanks for the great thread
 
#506 ·
2002 LS: I lost my 1 & 2 blower speeds about a month ago and 3 just went out yesterday. I just removed my blower motor resistor (Made in Mexico) per the great instructions from this thread --super easy and quick. Thanks for the post, I don't seek any help until consulting this site first!

I just order my replacement blower resistor (ACDelco 1581095) from RockAuto for $32.79.

This is my second blower motor resistor, does anyone know why these things keep failing? To me, it seems like heavy usage is the culprit (I use 1,2 and 3 the most and in that order). All wiring looks normal. Do the six metal coil contacts on the back of the resistor panel burn out?

Pics of my old resistor are attached.

93F

Thanks!
 

Attachments

#512 ·
Thanks SOOOOO Much!

Used your pictures and instructions to find and replace the blower resistor pack. When I got to it, there were burn marks and a melted connector pin like so many others talked about. Autozone, $28, and a couple hours total time...AC works again. HOrrible time for AC to go out, but thank to this site and members I saved $100's.

Awesome job!
 
#515 ·
Mine has been broken for 2 years. I had no idea why it only worked on the high setting but thanks to this thread I'm going to be fixing it just as soon as my part arrives in the mail. Thanks guys.
 
#518 ·
You may have to do some cutting and splicing

Be prepared. It may depend on who manufactured your replacement part, but the AC Delco resistor I received looked very different than the original. The wiring was a few inches to short, so I had to cut and splice the connector from the original onto the new one, extending it about four inches.

Nice to have high fan speed back though. Thanks for the write up!
 
#519 ·
Be prepared. It may depend on who manufactured your replacement part, but the AC Delco resistor I received looked very different than the original. The wiring was a few inches to short, so I had to cut and splice the connector from the original onto the new one, extending it about four inches.

Nice to have high fan speed back though. Thanks for the write up!
What gauge wire did you use?
 
#528 ·
Thanks. My Trailblazer lost fan speed 1 a long time ago, 2 a month ago and 3&4 last week. Checked out this forum and ordered the part # 89019100 from GMPartsShop.com as per info in this forum and installed per pictures in about 20 min. Could have been 5 min if I was only 20 years instead of 60. Thanks again. Rick
 
#529 ·
Thanks for all the info. It was a sinch to repair my Rainiers resistor. Just ordered an AC Delco resistor off ebay for $45 and got it in 3 days. The dealer wanted $150!!! and 1 week delivery! I told them where they could shove it... Only took about 20 minutes to change it out.:tiphat
 
#530 · (Edited)
ok so lets put a little spin on this one !!! :)
i replaced the connector on my tb in jan as the blower had quit working , checked the connector , surprise surpise the thing was melted , so i thought ,upon very close inspection, that the pins in the resistor pack looked to be ok, to re-use . two weeks ago , i find myself replacing the pigtail again , and the resistor pack this time ! after i had installed them i found that the wires would get warm in my fingers on the high (#5) possition .
now, being a mechanic of twenty plus years ,tells me that ,one; the connection at the resistor/pigtail is not sufficent to carry the load (amp wise)
or two ; my blower fan possibly has a problem at full load .
buying this vehicle used at 60000 miles the blower fan NEVER worked on high (#5) untill i replaced the melted pigtail

ok this brings me to my question ??? 1; is there a difference (in quality)of the different manufactures of the resistor board / pigtail ?? or ......
2; has there been problems with the blower fans ?? at any point ??
any suggestions????
 
#531 ·
1) Not sure we ever get reports of folks replacing them multiple times who ALSO report the brand they're using. At least I don't remember any, and I've got a pretty good memory for failure analysis issues like this.

2) Very seldom do we hear of blowers with high friction in the bearings that might mean high current is needed to run them. I speculated that internal winding shorts between layers on the armature windings would increase the current due to lower resistance. Nobody who was a victim of this sort of thing ever puts an ammeter on the motor to tell for sure what the proper current is.

You figured out the exact possible root causes I have, but compared to other misdesigned things in the vehicle, this one doesn't get a lot of attention.
 
#532 ·
i dont recall the first time i changed the connector , the brand of the connector, as i bought the vehicle used ,all i can do is suspect the resistor
board had not been replaced , so i would say it was oem.
the parts that i replaced it with came from carquest, and were not badged anything but , ...... the connecter ultimatly was made by bosch as it was badged as such ! I dont own an iductive clamp.... but i have access to one .
will post finding when/if i get the person to borrow the clamp to me :)
 
#533 ·
Hi folks! I just replaced the resistor assy. in my '04 TB and all the speeds now work :) only one (new) problem now .... The air isnt coming from my forward vents! :hissy: air comes from the defroster vents and the rear vent. Am I looking for a relay problem? Does anyone have a suggestion what this problem might stem from?! I pulled, checked, and cleaned the contacts of the rear AC fuses too.
 
#538 ·
just an update (if anyone read this); I think my problem may be the mode actuator as the others seem to be working correctly. I took off the trim pieces as discussed in other threads (and threads outside this site) and found three of them on my drivers side. I am making an educated guess at this point that the middle one is what I need to look at / replace. You would think these things should be simple to reset but apparently no one has the straight dope on that. Does anyone here know what I should be looking for when these things initially get power to them? should the motor axle rotate any? Any insight would be appreciated. :crazy:
 
#535 · (Edited)
#4 had been out, but then #5 went out and with the Hotter than H#ll summer I replaced the resistor about a month ago. After I replaced the part #4 worked for a day or so and then went out again, but at least #5 worked. All of a sudden today while going down the highway, #5 stopped working.

Can a resistor go bad that quickly? Should I replace the resistor again? There's got to be another problem if it keeps going out. Hate to take it in to a mechanic - they charge so much. :(

BTW, I used the instructions from this thread and had no problems replacing the resistor.

Marilyn
 
#536 ·
Hi Marilyn,

I would read back a few pages on this thread. It seems that there are some problems with the wire sizes and wires burning up. You may have to replace some of those components. As I said, I would go back a few page and see if that is the same thing you are having trouble with.

Jerry
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top