Hello guys, Got an interesting problem with my HVAC. So I'm working on.my 06 H3 and noticed that when I have my AC on, and make one click to the right, it goes straight from very cold to very hot. I have recalibrate my Hvac twice and still not working. I have been doing research and some are saying it could be just be the actuator malfunctioning or merely needs a resistor installed on the wiring harness. Can anyone give me a hand?

 

Bulletin No.:PIT4704A: HVAC Temperature Goes Full Hot When One Click Off Full Cold - (Feb 18, 2010)
Models:

2006-2008 Hummer H3

--------------------------------------------------------------------------------
This PI was superseded to update the Recommendation/Instructions. Please discard PIT4704.
--------------------------------------------------------------------------------

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:


Some customers may complain that the temperature will go to full hot when they turn the temperature one click off of full cold. The control head is defaulting to Emergency Mode (this provides HOT air for safety reasons which would be available to clear the windshield in Defrost mode). This will happen if the feedback voltage for the air temperature actuators are out of range.

Recommendation/Instructions:


Replace the HVAC control head with part number 25920831.


Bulletin No.: PIC4995A Subject: HVAC Temperature Goes Full Hot When One Click Off Full Cold- (January, 2014)
Models:

2006 - 2010 Pontiac Solstice
2007 - 2010 Saturn SKY
__________________________________________________ ________
This PI was superseded to update model years. Please discard PIC4995.
------------------------------------------------------------------------------------------------------

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern
Some customers may complain that the temperature will go to full hot when they turn the temperature control one click off of full cold. The control head is defaulting to Emergency Mode (this provides HOT air to clear the windshield in Defrost mode). This will happen if the feedback voltage for the air temperature actuators are out of range.

Recommendation/Instructions
Locally obtain a 60 to 68 ohm, 1/2 watt resistor, and install it in-line with circuit 1688, pin F of the HVAC control head. Install the resistor just behind the HVAC control head.

 

Have you had the HVAC Recall work done?

 

Just replaced my halogens in my hvac with leds

 

Whats the part number on the head? Updated head is 25920831
Some have installed inline resistor:

 

I had the exact same issue in my 09 and did the resistor mod, which fully resolved the problem. Full instructions on how to do the mod is available here. The issue is caused by the 5VDC reference signal from the control head to the stepper motors being out of range, which drives the system into a "fail safe" full hot mode. The resistor brings the voltage back into range and restores normal operation.

Hardest part of the whole thing was finding a local electronic store that sold resistors. \o/