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blower motor resistor

41K views 30 replies 18 participants last post by  the roadie 
#1 ·
oh well just drove the wife's t-blazer and the blower motor won't turn on 1-2 speeds 3,4,5 all work. did the search, seems the resistor is pretty common on these(mines an 03 with 94,000+).

Anyhow what I didn't see mentioned is that on top of loosing speeds it's not switching between defrost, dash vents, floor outlet properly either. Is this also indicative of a poor resistor?

Just trying to see what else(if anything) may be wrong here.
 
#10 ·
I Agree

I'd say it's 99% your resistor. Mine used to work only on 2,3,4 and sometimes 5. It's a $15 part and takes 510 mins to change, held by 2 bolts under the dash passenger side :thumbsup:
:iagree:
I just fixed mine this afternoon. It would BARELY blow any air from any position on my AUTOMATIC HVAC. Once in a blue moon it would kick on and blow, and then stay on 10 minutes after I stopped. Killed my original battery that way. I bought mine at the stealership for $109 Tax included, and it literally took 10 minutes to do. Now everything works perfect. Just in time for the COLD season!:woot:
 
#9 ·
Actually I work for a GM & Chrysler dealer in sales so I can get parts for my TB and parts for my girls Jeep all at cost, I believe I might have paid about $16.xx. But parts4chevys.com is the next best place :thumbsup:
 
#15 · (Edited)
Thanks everyone for your help. I ordered the module from parts4chevys.com - $71.45 (including shipping). Before I did I called around to a few auto parts dealers to see if they carried it. I was surprised on how many wanted to correct me on the word "module" for the word "Resistor". It appears that most of them carried the resistors, but none of them carried the modules. The only parts store to carry the module was the dealership - $103.38 (plus tax).

Now I have to wait until my module comes in... weather forecasts call for mids 20's (F) for the highs mid week next week. I sure hope I get it in before then! ;)
 
#16 ·
My First Post - just a quick thank you to all of you who post here. It really helps those of us not so knowledgeable. In this thread, I had the same issue of a blower not working. I educated myself here first, then went to Autozone. They said the correct part was the resistor - not the module. I showed them the one I'd taken out of my '03 Envoy - not a match. They could order one for $99.00.

I took the suggestion by another member here and went to Parts4chevys.com. Got the module for about $80, and the special they were running for TrailVoy (10% discount in January) will pay for the shipping charges. Way cool.

..now if it only works when it gets here. :)

Anyway, thanks again!
 
#17 ·
The module is for the auto climate control and the resistor is for the manual climate. Partsforchevy does not list the resistor for the envoy only the module. I had to look for it under the trailblazer. I've used partsforchevy a few time and was not really impressed(slow shipping and slow response to emails.).
 
#21 ·
Speed #5 does not work after replacing resistor

My blower had finally completely quit after several weeks of working on certain speeds when it wanted to. I ordered a new resistor module and replaced it. It now works again but not on Speed #5 (all the other speeds work). Have you seen this problem on a brand new resistor?
 
#22 ·
I had the same problem, 1 and 5 did not work and about a week ago 2-3-4 stopped working. I just replaced the resistor and still nothing works. What is the next step, replace the entire blower? I thought that maybe I installed the resistor wrong so I turned it around and that made no difference. What else could be wrong?
 
#23 ·
Did you find the other threads that tell you what fuses to check before spending any money? Just find those threads and check 'em.

Otherwise it's the motor or the switch. Hard to tell without a meter and looking at the connector on the resistor module. Do you have a meter? Or can you bring 12V from the battery to the blower motor connector and see if it spins?
 
#26 ·
Rear Cab Upper Vents

Hey guys, I just replaced my blower motor resistor. It would only work on 4 or 5 prior to doing it. Now it works sweet! The ceiling vents for the rear cab weren't blowing before and aren't blowing now, on any setting. Is there another blower resistor in the back passenger side that I need to change, looking for guidance.

I just started working on cars, and I am learning ALOT from this site because I absolutely love my Trailblazer. Thanks to whoever made this site, it makes the learning process pretty easy!
 
#27 ·
Welcome! Unless you have an EXT, you don't have ceiling vents. You might want to edit your profile.

Are you saying the rear blower never worked, or that it blows, but always comes out at floor level, not through the ceiling ductwork.

If you have an EXT, the rear blower speed control is a more expensive solid state module, and it's worth troubleshooting a bit more before replacing it.

Do you have a meter and know how to use it?

Check fuse #13 and #36 in the rear fuse block. There is another hidden fuse near the blower motor, but check the two other ones first. Are the lights on as expected on the rear control module? No reaction to any position of the front speed control switch?
 
#28 ·
Pretty sure it is an LT. Thats what it says on the side. There is a passenger side roof vent and a driverside roof vent in the second row seating. It comes out floor level fine. I actually took the rear paneling off today and checked the fuse above the blower motor, it looks good. No i don't have a meter and havent used one before. Also, I checked all fuses in both hood box and under second row seating. And correct, no reaction on any setting in front control switch. (Might I say your pretty quick in responses :p)
 
#29 ·
All I can suggest is buy some beer and bribe a friend who knows electrical troubleshooting. You've done all you can without knowing more and having a meter. Or paying a mechanic. Or spending $75-90 on the rear blower speed control module (more complex than the front resistor pack). Sorry.
 
#31 ·
Ummmmm, look at them? Manual means you have to set the temp with a slide pot and fiddle with it if it drifts. Automatic (digital display) means you just set the temp with a dial and the system makes it work.

Please read the Owner's Manual. It's a wealth of wonderful information. ;)
 

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