I just bought an '03 1500 QC Laramie with the 4.7 motor about 2 months ago. This morning driving into work, I turned the heat on (live in Fort Worth and first time I needed heat since I bought the truck). I have the dual climate control heater and selected heat for both sides. The passenger side vents had nice hot air coming out of them, but the driver side had cool air blowing. I moved the controls a few times, but always the same results. If I move the controls to cold, both sides blow cold air. It is only when I move the controls to heat that I get a difference in air temperature between the two sides. Any thoughts? or suggestions?

Thanks

 

This is very funny to me that somebody asked this question. I know very personally how this HVAC system works...very personally.

There's nothing wrong with the heater, there is something wrong with your air mixing doors not moving inside the HVAC. Either that or wires got disconnected inside. You won't be able to fix this, just bring it into a dealer and they will fix.