Rear hvac module discontinued. Can mine be repaired?

[76Nick]

Hey guys, so my hoe has the typical no rear heat issue due to the rear hvac module being bad. Dorman used to make a replacement however that seems to no longer be available. My question is, does anyone know how to repair my current one since this is a common issue? I figured maybe someone has done it or there is a way to do it, sort of like the lighting on the gauge cluster being able to be repaired by resoldering a connection in it. Thank you!

Nick

 

[Doubeleive]

Hey guys, so my hoe has the typical no rear heat issue due to the rear hvac module being bad. Dorman used to make a replacement however that seems to no longer be available. My question is, does anyone know how to repair my current one since this is a common issue? I figured maybe someone has done it or there is a way to do it, sort of like the lighting on the gauge cluster being able to be repaired by resoldering a connection in it. Thank you!

Nick

define bad and what part exactly? unless you smashed it to bits it has several different parts inside all of which can be replaced one way or another.
or are you talking about the roof mounted control switch? if so even if there are no "new" ones available there is probably a million used ones out there.

 

[Fless]

Upull or junkyard. Would be helpful for us to know what you're driving.

Mod work: I deleted the duplicate thread.

 

[76Nick]

Sorry didn't realize I duplicated it. I attached a picture. Its the module behind the rear passenger panel. I have an 03 Tahoe z71. Thank you.

 

[76Nick]

Also due to it being bad the rear of the truck just blows cold air.

 

[Doubeleive]

Also due to it being bad the rear of the truck just blows cold air.

have you confirmed it is the module?, what is the dorman replacement part number? have you looked on ebay for a dorman and/or used factory part number?
does the hold/cold actuator in back move both directions or is it just stuck on cold?
basically how much troubleshooting have you done? do you have a tech2?

 

[Doubeleive]

need all of that information otherwise we can't help much

 

[Doubeleive]

presuming you know for a fact the rear module it out here is brand new oem one

Genuine GM HVAC Control Module Rear ACDelco | eBay

<p dir="ltr" style="margin-top:0; margin-bottom:0;">HVAC Control Module Rear ACDelco Genuine GM. Brand new. </p>

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[76Nick]

Dorman 601-036. I do not have Tech2. The actuator is stuck on cold and won't move unless I power it manually with my power probe. I will bid on that unit. I looked a couple days ago and the only one on ebay was a used unit the guy was asking $295 for. Thank you

 

[Doubeleive]

Dorman 601-036. I do not have Tech2. The actuator is stuck on cold and won't move unless I power it manually with my power probe. I will bid on that unit. I looked a couple days ago and the only one on ebay was a used unit the guy was asking $295 for. Thank you

there is probable one in the rear of every 03-06 gm suv in the junkyards from coast to coast, there is at least a dozen of them about 10 miles from me, $2 entry fee and probably $25 for the part at pick n pull
if you go to the junkyard and of them with these part number's will work
21997590 15832319 15181175 15763056 15185966

 

[76Nick]

Yeah I thought about grabbing one from the junk yard but didn't want to end up with another bad one. From what I understand this is a fairly common problem. That's why I asked if anyone knows how to repair them. Assuming its probably a component inside that goes bad and needs to be removed and a new one resoldered, or even just a solder joint that cracks and needs to be done again like with the gauge clusters.

 

[Doubeleive]

Yeah I thought about grabbing one from the junk yard but didn't want to end up with another bad one. From what I understand this is a fairly common problem. That's why I asked if anyone knows how to repair them. Assuming its probably a component inside that goes bad and needs to be removed and a new one resoldered, or even just a solder joint that cracks and needs to be done again like with the gauge clusters.

it's not that common, it happens but 99% of the time it is a bad actuator, I would guess that you would probably not find a bad one in the junkyard and if you did most yards give a 30 day warranty (exchange) anyway

 

[76Nick]

it's not that common, it happens but 99% of the time it is a bad actuator, I would guess that you would probably not find a bad one in the junkyard and if you did most yards give a 30 day warranty (exchange) anyway

I'll have to make sure before I buy one providing I need to go that route. Thank you

 

[Fless]

Dorman 601-036. I do not have Tech2. The actuator is stuck on cold and won't move unless I power it manually with my power probe.

This seems to indicate that the module isn't getting the power, ground, or perhaps the signal from the overhead control to change.

If the truck has the AUTO controls, is it being commanded hot in AUTO, or by setting the control temp manually on the overhead control?

 

[Doubeleive]

I'll have to make sure before I buy one providing I need to go that route. Thank you

in the meantime you can turn it to hot and unplug the actuator so you can have heat until you get it fixed

 

[milano]

Have you put in a new module yet? Did it fix the issue?

 

[Fless]

Have you put in a new module yet? Did it fix the issue?

The OP hasn't been on here since Feb 11th. I wouldn't expect an answer.

 

[Jkpii2000]

Do not buy a Dorman rear climate control module! I bought one about 5yrs ago and it was hell. Every 3 days my battery was dead. After months and months of diag I put my gopro in the Tahoe (2 weeks straight in different places) and head the rear blower motor turning on. It would run for hours off and on. Through my work (18yrs as a UPS diesel mechanic) I met the Dorman rep. I told him about my issue and he said thousands of people had a problem with them. They were know to have a problem from a program issue. Just thought I would share that with you. I’m back in the same boat as you. I went to the junk yard and pulled one about 4 years ago and it went out a few months ago. I’m going to pull mine apart and see if I find any broken/cracked solder joints. Hopefully someone knows a fix on this as it’s been a problem since 2009. Gm even came out with a updated module and it didn’t fix anything.

 

[Stickle]

Morning all, just wanting to revive the thread with a question for the electronic guys. What, specifically, is failing inside the control mod? Is it bad solder, a bad transformer, loose pins? I see there are a few guys who refurbish them (all seem to be in Texas), just curious what the fix is. I'm in Canada so the ebay finds for me are expensive thanks to shipping, even worse with the exchange rate. A junkyard is an ok option unless you pull one and find it's fubar as well. Is there a way to test the mod board with a multimeter in the field?

 

[Doubeleive]

Morning all, just wanting to revive the thread with a question for the electronic guys. What, specifically, is failing inside the control mod? Is it bad solder, a bad transformer, loose pins? I see there are a few guys who refurbish them (all seem to be in Texas), just curious what the fix is. I'm in Canada so the ebay finds for me are expensive thanks to shipping, even worse with the exchange rate. A junkyard is an ok option unless you pull one and find it's fubar as well. Is there a way to test the mod board with a multimeter in the field?

never looked into it, there are tons of these around the yards I would just go grab a used one.