GMC Repair: ac system 2002 suburban, hvac control systems, valve actuator

Question
QUESTION: Hi,
with the front and rear ac controls set on auto, the rear only blows high cold no matter what the outside temp, front may blow heat but the rear still is high cold.  the fan on the reas controls will lower the fan speed but cannot get cold off.

suggestions appreciated.

bobklein

ANSWER: Hi
Sounds like the rear temp. valve actuator is stuck electrically, or the valve itself is stuck mechanically (very rare). I would HIGHLY suspect the rear temp valve actuator. If you know someone with a good quality scan tool, you could probabally scan the HVAC control systems, and see if there is a code set for the rear HVAC actuator.

---------- FOLLOW-UP ----------

QUESTION: not a question, just a thank you.

thanks

Answer
Hi
If any further assistance is needed, please, do a thank you follow up, I set my vacation dates high due to the extreme volume of emails I recieve in a short time.
The rear HVAC actuator is located passanger side, rear under the large trim piece next to the thrid row seat.
I really hope this helps
Pawl