Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner
1 - 20 of 24 Posts

·
Registered
2003 chevy trailblazer_lt_ext
Joined
·
22 Posts
Discussion Starter · #1 ·
Hello everyone,

I can sure use some help if any know what's wrong with my suv. I own a 2003 Chevy Trailblazer LT with the duel digital thermastat controls. Off and on over the last few summer when the fan was blowing, no air would come out. Then minutes (sometimes several) later it would start working fine. Now within the last month if you turn the air or heat on and put the fan on high, somtimes it barely comes out. Then maybe a few minutes later it starts blowing like it's suppose to.

Please help.

CLeib (new member)
 

·
Banned
2004 gmc
Joined
·
26,181 Posts
That system doesn't have the discrete resistor fan speed module that fails often for the analog control folks. But the continuously variable fan speed control module can have a corroded/oxidized/intermittent power connection on the module.

Remove the lower passenger side kick panel from under the dash, and tilt down the glove box and poke around back there. The control module has one FAT red power wire, and the 2-wire harness going to the blower motor has a purple power and a black ground. Any of those could be heating up the harness and causing the wire insulation to start cooking and turn brown. Wiggle and examine closely and you'll probably find the issue. As to whether or not you can fix it, or get an electrically experienced helper/mechanic, I can't tell.

It's item #12:

 

·
Registered
2003 chevy trailblazer_lt_ext
Joined
·
22 Posts
Discussion Starter · #3 ·
reply

Thanks for the reply. I'll give it a shot either today or tomorrow and hopefully fix it. Lord knows it will make my wife happy!
 

·
Registered
2003 chevy trailblazer_lt_ext
Joined
·
22 Posts
Discussion Starter · #4 · (Edited)
still problems with blower

Hey "the roadie" or anyone else out there:

I took off the glove box and wiggled all the wires that is associated (I think) with the blower and visually looked at them and the blower still does not work correctly. I truly appreciate the last response from the roadie. Any other suggestions will be greatly appreciated. It got to over 85 degrees here in southern Illinois and my wife was not happy at all today. Only have 5 or 6 payments left and I got to get the air conditioner working properly or she'll start talking trade. PLEASE HELP!!

P.S. The compressor in the engine is definately working. No matter what different fan speed you set it just barely blows out any air. The rear blower is working just fine. Again, PLEASE HELP!!
 

·
Banned
2004 gmc
Joined
·
26,181 Posts
1) I assume, since you didn't mention it, that all the displays for the control module are OK.

2) The problem is in the fan, the speed module, or the wiring. To distinguish among them requires a meter and knowledge how to use it, or throwing money at the problem like a new speed module. Do you have a meter? I could give you the schematic if you want to go poking about for voltages.

3) If you have a meter, start by confirming the fat red wire to the speed module has 12V. Then force the fan speed to high, and see if the purple to the blower motor has 12V and the black has zero.

4) If you don't have a meter, buy some good beer and hold a sign out on the street:

Free Beer for Electrical Troubleshooting Help!

Or drive to San Diego with a case of Arrogant Bastard Ale. I'll do it. :tiphat
 

·
Registered
2003 chevy trailblazer_lt_ext
Joined
·
22 Posts
Discussion Starter · #6 ·
Now my wife just got back from Walmart. The air didn't work on the way but did on the way home. It was on high and you could not turn it down even when moving the digital fan control. The digital display works just fine. Also, when she turned off the trailblazer, took the key out, the blower motor was still blowing!!

Didn't know if this would help with the diagnosis or not.
 

·
Banned
2004 gmc
Joined
·
26,181 Posts
It makes it crystal clear. The speed control module is bad. Nothing else could cause those symptoms. She saved you a bunch of time and troubleshooting!

Do you need to turn off the blower now so it doesn't kill the battery? Fuse #35 under the hood.
 

·
Banned
2004 gmc
Joined
·
26,181 Posts
I would rate them a 2 wrench job on a scale of 10. Swapping a gas cap is 1 wrench. :yes: You have to own *some* tools.

Your part number is GM #89018964, AC Delco, #15-80906 if your module is labeled 52416100.

It may also be an earlier design, ACDelco #15-80567, GM #89018778 for modules labeled 52413530 OR 52409643

Available at aftermarket parts stores, not just the dealer, so they're cheaper than you might think. $50-80
 

·
Registered
2004 chevy trailblazer_ls
Joined
·
694 Posts
Now my wife just got back from Walmart. The air didn't work on the way but did on the way home. It was on high and you could not turn it down even when moving the digital fan control. The digital display works just fine. Also, when she turned off the trailblazer, took the key out, the blower motor was still blowing!!

Didn't know if this would help with the diagnosis or not.
LMAO ROTF! :dielaugh::dielaugh::dielaugh::dielaugh:I have this mental image of your wife driving home looking like this inside the car, not to mention freezing...
 

Attachments

·
Registered
2003 chevy trailblazer_lt_ext
Joined
·
22 Posts
Discussion Starter · #11 ·
Thank you again!!

I'll try and locate one tomorrow at either our NAPA store or Autozone. Hopefully they will have one in stock.

After I get this fixed I would like to get your advice about the driver's side heated seat not working (top and bottom went out at the same time), and trying to find a cheap/used window regulator for the rear driver's side door.

Thanks again.
 

·
Registered
2003 chevy trailblazer_lt_ext
Joined
·
22 Posts
Discussion Starter · #12 ·
The difference between that woman and my wife is my wife's hair is short and that woman looks way happier than my wife when she got home last night!
 

·
Registered
2004 chevy trailblazer_ls_ext
Joined
·
7 Posts
Air Conditioner directional switch

Does anyone know the cause of the directional switch problem? I can not change from the window deffoger to send air to the front seat or anywhere else. It doesn't seem to function no mater how it is turned. Is it the same control module issue or is the switch and connectors the problem?:crazy:
 

·
Registered
2002 chevy trailblazer_ls
Joined
·
31 Posts
After further searching for a reason why my air conditioner is stuck on I found this thread. My Trailblazer is an LS and I just replaced the fan motor resistor because number 5 stopped working. Is there a difference in the resistors for the climate control model and bone stockers? I noticed when I changed the resistor the new one looked different and has a red wire instead of a purple wire. Is it possible they gave me the wrong resistor and it is causing my AC to be stuck on?
 

·
Western Canada Chapter
2003
Joined
·
6,411 Posts
The non-climate control blower motor resistor is this part number:

A/C Blower Resistor #89018604
Resistor that regulates blower settings 1-4

and only about $30 - $35
 

·
Registered
2002 chevy trailblazer_ls
Joined
·
31 Posts
The non-climate control blower motor resistor is this part number:

A/C Blower Resistor #89018604
Resistor that regulates blower settings 1-4

and only about $30 - $35

Not sure if I was clear on my post or I'm not understanding yours. I have an LS with no climate control. The fan speed number 5 went out so I ordered a new resistor and replaced it. The fan speed number 5 now works, but when I was checking everything out I noticed that my AC is running when the fan is on regardless of the position of the push button that controls the AC. I don’t know if the two are related or not. When I found this thread I started wondering if there is a difference in the resistor for the climate control models and the non-climate control models.

Additionally, When I replaced the resistor I noticed that they obviously look different and the wire colors also changed. This is the reason I am questioning the resistor being the root cause of my AC constantly running.

Of course I threw the old resistor and box from the new resistor away and yesterday was garbage day. :ugh:

Thanks for any input or help.
 

·
Registered
2006 chevy trailblazer_ls
Joined
·
172 Posts
Same thing bit me in the butt yesterday

Went to the bank around 3:00 PM and all was working fine. Left work at 5:00 and I had no air. Blower won't work on any setting.

It's 95 in July in Tupelo, MS. And I am getting married Saturday, so money is tight right now anyway.

:mad:
 

·
Registered
2003 chevy trailblazer_lt_ext
Joined
·
1 Posts
Roadie: You fixed my A/C!

I would rate them a 2 wrench job on a scale of 10. Swapping a gas cap is 1 wrench. :yes: You have to own *some* tools.

Your part number is GM #89018964, AC Delco, #15-80906 if your module is labeled 52416100.

It may also be an earlier design, ACDelco #15-80567, GM #89018778 for modules labeled 52413530 OR 52409643

Available at aftermarket parts stores, not just the dealer, so they're cheaper than you might think. $50-80
Roadie,

Just wanted to say thanks for your expertise and willingness to help others. This is exactly the problem I was having (digital air conditioner control, no control over blower speed, blower keeps blowing even after key removed from vehicle).

This was the exact part I needed. Ordered it from gmpartsdirect.com, cost $67.35 plus S&H. Got here in about a week or so. Changed it in about 20 minutes; only tool needed is a couple small sockets to remove the mounting screws. The Part Numbers on my old module were (1P)52495874 and (12V)251946786, which has evidently been revised to a NEW part number -- GM#89018778, which is what I ordered.

For those wondering, this part is located on the passenger side of the vehicle, under the dash, above about where the passenger's right foot would be located. You have to remove the black plastic kick panel, right underneath the glove compartment. There are wires plugging into it from the Digital Control, and wires running FROM it that plug into the blower (right behind the glove compartment).

So the fix is to unplug both sets of wires, and take the 2 screws out that hold it under the dash. Then install the new one. That's it.

Again, I'd like to thank Roadie for his knowledge and helpfulness... this is especially invaluable these days, when money and time are so short! God Bless!
 

·
Registered
2007 chevy trailblazer_lt
Joined
·
10 Posts
Blower Control Module

I have a 2007 Trailblazer LT and, after reading this thread, it appears my Blower Control Module has gone bad. The blower started blowing on full power on Tuesday and the only way to shut it off was to pull the fuse under the hood. I have not yet pulled the passenger kick panel off and gone looking for it, since I just found where it might be and that it is probably the problem, but have been trying to find a part number online and have not been able to. I could use some help. My Trailblazer has the auto climate control.

Thanks in Advance.
 
1 - 20 of 24 Posts
Top