# 2004 GMC Temp Controls (A/C-Htg)



## TXplugger

I have a 2004 GMC Sierra that has the dual climate control. Last week I noticed the passenger side temp was staying cold while the driver side was blowing warm air and both were pushed up to the "red" zone. Is the problem the control switch/dial itself or something internal? Any help is greatly appreciated.


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## patwilson

*GMC A/C and Heat*

I have a 2003 GMC Sierra that has the dual climate control that is doing the opposite???? I would like to know my self. Dealer wanted lots of $$$
To check this out. I found that if you turn the system off for 1-2 minutes
and back on it will work after that????
Please help.......


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## Justin_Time

I have had the same problem with my 04 GMC Z71. It seems there is some type of door that sticks causing this problem. I can turn the AC off, then back on, and it typically solves the issue. It seems strange that we are all having the same problem.


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## Txmm13

Its a bad relay switch in the AC.


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## patwilson

:question::question::question:


Txmm13 said:


> Its a bad relay switch in the AC.


Where? And how do you know for sure? Do you know the cost or the correct name of this relay? The location on the truck where it is mounted?
Thanks for help, Pat


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## reelthreat

It is called the AC control module (around $100). I had to replace mine about a year ago in my 03 Z71. I will look for the part number and post it. Also if the AC is just blowing hot air and will kick on every once in a while it is the AC cycle switch ($30). Both are real easy to replace and both are very common problems.


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## jeff.w

If you can find the part #, I recommend getting it from www.rockauto.com

I've bought several things from that website, and the price and customer service have been outstanding.


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## BIG PAPPA

*no no no*

It's not the cheap cycle switch. You say one side is hot and the other is cold?? if so, it an AC actuator motor(that opens/closes doors) in the ac duct system. some are fairly cheap but others are expensive to replace which requires removing the entire dash assembly to replace. Take it to a respected dealer for diagnosing. the actuators cost $238.46 each and i think your blend door actuator is going bad. the labor can run anywhere from $170.00 to $510.00 depending on which one is bad. The blend door actuator runs about 2 1/2 hours labor to diagnose and replace. @ $85.00 per hour that would be $212.50 plus $238.46 for the part, tax around $17.28, and a total of $468.24. anytime you have ac coming out one side and heat out the other, it will definatly have a bad actuator in the ducting.


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## reelthreat

ACDELCO Part # 1580567







{replaces 93803636 #1572909, 52495874, 89018778, 93803636}
MODULE,HTR & BLO & A/C CONT EXTENDED CAB; w/A/C FRT AUTO/AUX CONT(CJ2)









$67.89$0.00$67.89









Here is the part ya'll are looking for. PM me and I will give you details...


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## reelthreat

BIG PAPPA said:


> It's not the cheap cycle switch. You say one side is hot and the other is cold?? if so, it an AC actuator motor(that opens/closes doors) in the ac duct system. some are fairly cheap but others are expensive to replace which requires removing the entire dash assembly to replace. Take it to a respected dealer for diagnosing. the actuators cost $238.46 each and i think your blend door actuator is going bad. the labor can run anywhere from $170.00 to $510.00 depending on which one is bad. The blend door actuator runs about 2 1/2 hours labor to diagnose and replace. @ $85.00 per hour that would be $212.50 plus $238.46 for the part, tax around $17.28, and a total of $468.24. anytime you have ac coming out one side and heat out the other, it will definatly have a bad actuator in the ducting.


Trust me on this one... It is the AC control module. I had the same problem (however, mine is Chevy) hot on one cold on the other and vice versa... then hot on both when only cold is supposed to blow then cold when hot is supposed to blow. I spoke to many mechanics and my buddy who is an AC specialist and they all said the same thing, it is a real common problem from 2000 to 2004 GMs with dual climate control.


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## patwilson

reelthreat said:


> Trust me on this one... It is the AC control module. I had the same problem (however, mine is Chevy) hot on one cold on the other and vice versa... then hot on both when only cold is supposed to blow then cold when hot is supposed to blow. I spoke to many mechanics and my buddy who is an AC specialist and they all said the same thing, it is a real common problem from 2000 to 2004 GMs with dual climate control.


pm sent


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## 6.5 shooter dude

It is a quick and easy fix 1 plug and 3 screws down by the floor above the transmission hump there is a blend door actuator that goes bad we change them all the time pm me or call me if you need help


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## 2slick

*Try this....*

Before replacing anything, try unhooking the battery for a few minutes. Sometimes this will work. My son had to do this a couple years ago on his 04 Chevy; no more problems after unhooking the battery for a few minutes.


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## dr. redfish

I have 2 04' chevrolets and each have the same problem. Wait until you start having instrument clusters go out. I've had 3 go bad on the same vehicle and the cost is about $400 each time. Chevrolets have pittiful electrical systems.


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## TheGoose

I'm getting my 03 replaced this week under warranty. Less than 70K miles.


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