Blower Motor/Module? Problem - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

328ferrari · #1 03-09-2007, 06:06 PM

I have a 2003 Envoy XL with Automatic Climate Control. The front blower does not work no matter what speed I set the fan switch to, however the rear one does work. I checked the fuses and they all seem fine and I checked the blower motor itself and it runs fine when I connect separate 12 volts to it. From reading the other posts, I believe the problem may be the blower module. Can anyone confirm this? If it is the module, GMdirect indicates the part number required is #88892976 while another poster seemed to think the correct module is #89018778. Appreciate if any of you have any thoughts? My wife is tired of driving around in the cold.
Thanks

328ferrari · #2 03-09-2007, 06:38 PM

Well I am now really confused -- went back to vehicle to play around some more. Removed blower motor from bracket, but left wiring hooked up. I now was able to get motor to turn however the switch to increase the speed of the fan had no effect on the fan at all. I could increase or decrease the switch, but the fan continued to run at the same speed. However the item which was truely amazing is the fan motor ran at a slow speed when I turned the ignition switch on and the fan motor turned at a fast speed when I turned the ignition off. I had read where the fan turns for a few minutes after the ignition is turned off, however why would ignition on vs. off have any effect on the speed of the fan? Also, shouldn't the switch which controls the speed of the fan have some effect?

I left the ignition key off for a few minutes and the fan motor stopped turning. Then I turned the ignition key back on hoping the fan motor would begin turning again -- but no luck -- I turned the key on, off, pressed all sorts of heater control buttons, but the motor would not turn.

Hopefully someone out there knows exactly what the problem is. I am sure I do not have ghosts in my garage. Or perhaps I do!

Thanks

shdtree3 · #3 03-14-2007, 11:06 PM

My 04 TB just started doing the same thing, some times it works most of the time it does no, manual or automatic mode, with or with out the a/c running. A coworker said he had the same problem in his two chevy 1500 trucks. Something about a ground wire not making good connection. there are 3 Service bulletins for the 04 TS that may take care of it. Will let ya know.

328ferrari · #4 03-15-2007, 10:00 PM

Well I ended up removing the module which is wired between the HVAC controls on the dash and the front blower motor. It is positioned under the glove box next to the blower motor. The part number on the module is #52495874. I then went to GMdirect.com and typed in this part number. The response was this part is no longer available and superseded by #89018778, which is the same number another member posted as being the correct module part number. I was 90% sure this is my solution so I ordered the part. It is suppose to take about a week to obtain. Upon installing the module I will let the board know if this is the solution--- I sure hope so.

lekmedm · #5 03-17-2007, 04:44 PM

Quote:

Originally Posted by 328ferrari

I have a 2003 Envoy XL with Automatic Climate Control. The front blower does not work no matter what speed I set the fan switch to, however the rear one does work. I checked the fuses and they all seem fine and I checked the blower motor itself and it runs fine when I connect separate 12 volts to it. From reading the other posts, I believe the problem may be the blower module. Can anyone confirm this? If it is the module, GMdirect indicates the part number required is #88892976 while another poster seemed to think the correct module is #89018778. Appreciate if any of you have any thoughts? My wife is tired of driving around in the cold.
Thanks

I've just run into the same problem yesterday duing the big snow we got here in the NE (damn that Murphy's Law!). Anyway, can anyone elaborate as to why there are 2 different part numbers? I think I'll also order the 89018778 module since someone else has used it successfully, but I'd like to know what makes the other module different other than the $20 difference in price.

On Parts4Chevys they have the following part descriptions:

89018778 : Hvac Controls Blower motor Control module

88892976 : Hvac - Controls - Auxiliary heater & ac - Control module Control module, envoy/trailblazer 2002 - 2007

Wht's the difference?

Ideas...?

328ferrari · #6 03-23-2007, 08:18 PM

Today I received the part and installed in the Envoy -- Voila!!! Blower works fine -- when turned on, the blower blows, when I adjust the speed I can hear the blower react as it should. It appears that I have found the problem.

To reiterate, #88892976 is the original part which is superseded by #89018778. I installed part #89018778, however can not explain why GM changed the part -- perhaps #88892976 was found to be unreliable.

LEKMEDM, good luck with your repair.

rduz · #7 04-05-2007, 12:15 AM

I bought a new one at gmpartsdirect.com, and when searching out the old part number, 89018778 is listed as the replacement.

Interestingly, the ACDelco cardboard box that the part comes in lists the GM# as 89018778, but the actual label on the part lists (1P)52414530 and (12V)206978376.

This part is for vehicles with automatic climate control. I think the manual switch versions use a different part.

lekmedm · #8 04-05-2007, 11:39 AM

Quote:

Originally Posted by 328ferrari

Today I received the part and installed in the Envoy -- Voila!!! Blower works fine -- when turned on, the blower blows, when I adjust the speed I can hear the blower react as it should. It appears that I have found the problem.

To reiterate, #88892976 is the original part which is superseded by #89018778. I installed part #89018778, however can not explain why GM changed the part -- perhaps #88892976 was found to be unreliable.

LEKMEDM, good luck with your repair.

Thanks for the good wishes.

Well, I finally got around to putting in the new module, and, unfortunately, it didn't solve my problem. So my next step was to replace the blower itself with a $40 used one from a salvage yard and that did the trick!

Now I have an extra module. Can anyone use one? Send a PM!

1dadalex · #9 08-13-2008, 03:10 PM

I have the same problem as described with my 03, Envoy, with climate control. After reading the postings, and checking the fuses, I believe it is the blower module. If you still have the extra module, I can use it. Thanks for all the threads.

fake93cobra · #10 09-07-2008, 12:58 PM

I also have the same problem. 2003 envoy w/auto climate control. Fan sometimes comes on at various speeds. Does not usually respond to controls.
Rear unit works fine. Order part# 89018778 from gmpartsdirect.com. I will post back after parts comes in and replaced.

Thanks for all the posts and pictures. Great site!