2004 suburban air cond on driver side goes to heat while driving


#1

Passenger side stays cold as does rear unit. Have to stop, cut off engine wait 3-5 seconds and start again. everything is fine for about 30 minutes of driving.


#2

Not familiar with zone question. both front thermos are set to same setting. Only driver side dash outlets are putting out very hot air.
Thanks


#3

Assuming you do not have separate controls for the driver side and the passenger side, then my guess is it is a vacuum problem. You may have a vacuum leak or just weak vacuum. On most cars the heater controls are managed with vacuum. A small leak can cause what you describe. Let me guess. Right before you notice the heat, you accelerated, like maybe from a traffic light or to pass a car?


#4
I read you reply so you do have separate controls.  My money is still on the vacuum issue, but just not as strongly.

#5

Good Lord Star; give this nonsense a break.

Listen to Mr. Meehan instead.