Mechanics

HVAC TEMP DIAL NOT WORKING

2007 Hummer H3 • 5 cylinder 4WD Automatic • 87,000 miles

I have a 2007 Hummer H3, I5. The HVAC temp dial is not working properly. On full cold it works fine. Move it 1 click toward warm it goes full warm. I've replaced the left and right actuators that would affect air temp flow. During HVAC calibration both actuators move. When trying temp dial, only the left actuator moves and it goes the full 90 degrees. I've also replaced the HVAC control unit (entire unit with control dials). What else should I be reviewing?
Avatar
Azneville
July 4, 2011.



1. Ignition on engine off
2. Turn TEMP dial all way to right
3. Turn blower control all wat to right
4. Turn mode selector all way to left
5. Simultaneously pressand holdthe A/C and defrostbuttons until LED flashes6. LED stops calibration complete This what you did?


Docfixit
Jul 4, 2011.
Yes, that is the calibration that I performed. I've had the same symptoms with actuators swapped between left and right, new actuators used and a new control unit in place. Both actuators work in calibration mode but not in regular use.


Tiny
Azneville
Jul 4, 2011.
Have you tried having it scanned? Let me do some research you have replaced most possible components


Docfixit
Jul 4, 2011.
Have not had it scanned yet.


Tiny
Azneville
Jul 4, 2011.
Scan could help Contorl head is the fix problem is none about and head does the fix. Have found one case where mode actuator was the fault


Docfixit
Jul 5, 2011.
Had it scanned - P0014 was the only stored code and that would likely be unrelated.

New symptom: last week the battery died. After I got it restarted the temp dial would only stay on cold unless moved all of the way to hot. Once moved all of the way to hot, the right actuator would move down incrementally to cold. Once it hit all the way cold, it would not move back up unless the dial was moved to full hot. During this time the left actuator did not move all at, unlike before. After a few tests back and forth the right actuator stopped moving at all.

I performed the HVAC calibration again and the original symptoms reappeared where only the left actuator was moving, and it would move the entire range to full hot when moving one click off cold.


Tiny
Azneville
Jul 10, 2011.
I have the EXACT same problem in my 2007 H3. Did you ever find the problem and solution?

I would really appreciate any kind of help you can provide on this issue. I've tried everything like you and am pulling my hair out trying to find the cause.

Ziggy


Tiny
Ziggymon
Nov 29, 2011.
I have the exact same problem with my 2007 H3. Did you ever figure out the problem?

Thanks - Ziggy


Tiny
Ziggymon
Nov 29, 2011.
No, didn't get it fully fixed. Have replaced both actuators and the control unit. Dealer claimed it was actuators and replaced them (after I replaced the control unit) and it works better, but not properly and not consistently. Moving it one click off of full cold still produces nearly full heat though that's better than before when it went all of the way to full heat. It did work well for about a week or two.


Tiny
Azneville
Nov 29, 2011.
Thanks for the update! I wonder if it could be the connectors not making full contact. I have read where this was a problem with these vehicles.


Tiny
Ziggymon
Nov 29, 2011.
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