Heater blows cold air

I have a 2000 GTP and the heater blows cold air out even after setting the dial to 90 degrees (or any temp). One thing that is puzzling, is that if I turn on the passenger temp controls, that side of the car gets hot but the driver's side stays cold.

Any ideas where I could start to look?

No one? It's pretty damn cold out and my toes are turning blue.

Paul, looks like the mechanics of your car are ok. The problem is with driver side temp controls. Hope this helps.

Paul, looks like the mechanics of your car are ok. The problem is with driver side temp controls. Hope this helps.

I figured that much. Do you think it could be a thermostat problem? Does the car have two of them since there are two controls?

Thanks for the help!

Nope, everything on the engine compartment is the same as a car with one temp control, the main difference is in the in dash routing. Instead of having one flap to coordinate cool and hot air.
It is divided in 2 and eahc half controlled by each temp control.

Try calling your local dealer and asking them very very nicely to fax you over the diagnostic tree to you. You can follow it untill it leads you to the problem, but I'd bet it's a stupid vacuum line fell off somewhere.

I definetly agree with Creepjon. On My Z-34 if one of the vaum lines fell from the MAP sensor when accelerating the A/C would only work on Windshield Defros position and no air flowing into the cockpit thru normal vents.

I used to have a similar problem, except the opposite of what you describe.

My A/C would only blow cool air out of the driver's side no matter what the climate control was set at. I even double checked that the passenger side climate control was off. It ended up being a problem with an actuator valve thingy somewhere in the A/C piping. It was fixed under warranty. The cost would've been somewhere in the ballpark of $200.

If your car has digital climate control, there's a diagnostic mode you can enter by holding down both climate control buttons for several seconds. I don't have the link to the website describing the different variables, but it will tell you if there's a problem somewhere in the A/C system. If I can find the link, I'll post it here.

My 1999 GTP started doing the same thing this weekend. The passenger side will not blow heat regardless if it is the dual zone mode or not. I am planning on checking to see if there is a blown fuse, which is the extent of my vehicle maintenance knowledge. It is probably going to be some kind of computer or software problem though. Let me know how much it costs to fix if you have it diagnosed and corrected.

It is not a big priority for me though. This is my wife’s car which drives 3 miles to work in. We only noticed this week on a road trip that we took together. The temporary fix for us, was to close the 2 passenger side vents, and point the middle vent in the passenger direction. Also, since the defrost seems to work properly, it will blow a uniform temperature on both sides.

I started having this problem, took apart the lower half of the dash (below steering wheel) and noticed that the actuator on the dvr side was working. I'm making an assumption that it's actual door that the actuator is driving is functional. Nothing in the service manuals that I bought describes this problem. I am wondering if it may be a HVAC controller problem...possibly with the closed-loop control. Not sure yet.