Question about 2003 GMC Sierra 2500HD

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My climate control starts blowing hot air while a/c is on

When I have the interior temp. set to around 70 degrees and it's 95 degrees outside, the passanger side (only) starts to blow hot air regardless of where the temp. is set to. Sometimes shutting off the vehicle (which isn't an option when doing 65mph on the freeway) will work, but only temporarily, and sometimes turning the passanger temp control all the way to hot will result in a gradual cooling. Once the air starts to blow hot when dial is turned to warmest setting, if I turn the dial to the coolest setting, it will start to blow cool. Most of the time the cool air is only temporary, but once in a while it lasts for a while.
I usually end up switching the dial from coolest to warmest, get a few minutes of cool air, then it starts to blow warm. Turn it to warmest and once cool air flows, turn it back to coolest. This is only temprary, and eventually I end up with full smoking hot air blowing from my passanger vents. I get frustrated, turn the climate control off, roll down the windows and sweat my tackle and berries off. PLEASE HELP ME! everytime I take it to the dealer it costs me a small fortune, and I'm desperate as my wife won't ride in it till I get it fixed and I hate driving her KIA.

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Make sure you have fully charged AC sytem first, if so Im sorry to tell you this but this is a difficult deal.you may not be able to correct this without taking it to a repair shop with gm scan tool. Reason being the actuators for the hvac that most likely are malfunctioning from either them or another component being bad , require recalibration.The other reason would be the body control module related.It would have to be scanned for U codes which can effect the hvac control.Sorry but thats what I know.

Posted on Sep 06, 2009

Testimonial: "Tahnk you for your prompt reply. That is about what I figured I was gonna hear, on to the shop I guess."

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