I have a 2006 Silverado reg. cab, 4x4 and am having an issue with the heater/fan/ac temp control. When I first turn the truck on everything works normal and fine. After about 20 minutes of the truck running, the drivers side vents start blowing hot air, even when the temp control is set to cool. I have no control of the temperature on the driver side and it just blows HOT. The passenger stays the same and has no problem. When I turn the truck off and then back on, everything goes back to normal.

Has anyone had this happen in their truck and/or know whats going on?

thanks
thomas

 

I think the new trucks work on mixing air using flaps. Check for a vacuum hose problem. Just a thought.