I have a 2002 Ram 1500 quad cab. My heater blows warm air out of the passenger vents but blows cool air out of my driver side vents. I DO NOT have dual climate control. I took it to my Dodge dealership but they "couldn't find a problem". has anyone had this problem?

 

Unfortunately, I think you are going to have to take all the dash apart and follow the vents and see where the warm air is getting in at.

 

The trap door system that redirects the air from floor to dash to defrost sucks in my 02 also!!! it never completely closes the floor vents off on the passenger side so the ladies get cold feet lol! (A Crown Royal bag fixed this problem for the summer.)

As to your problem I bet it is in that same area, I would try a shop specializing in car heating and air, or tear into it yourself and watch the little doors open and close as you change settings. Then figure out which one aint doing his job and get rid of him!!!