Problems With Climate Control

Hello, I have an 07 malibu Maxx SS which seems to have developed a problem with the heating/cooling system. When the car is first started, once the coolant temp starts to rise the heating system works
fine. However, at the point that the car is fully warmed up, the temp can't be controlled: it blows cold air (even with the A/C switch off), unless the temp is turned up to about 85 degrees at which point it blows hot air. The car has been sitting at the dealer's for two days now and they say they can't figure out the problem. They know there's a problem but can't isolate it. Do any of you have some ideas? I'd like to be able to tell them by tomorrow so they can really get to work and fix or replace whatever needs fixing.. thanks in advance.
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Hi. I have a 07 Yukon that also has heating/cooling problems. Sometimes the driver side will blow hot air and the passenger side will be cold (with A/C on) even though the temp settings are the same on both sides. Other times the heating will not work. So far, I have been able to reset this by running the temp setting for a few minutes at maximum setting on both sides. That's not fun in the summer. Than shutting off the engine, waiting a few minutes and then starting again.
On a different note, sometimes the cruise control does not set, and even does not switch on. Stopping the vehicle, cutting off the engine, waiting a few moments and then starting again fixes this also. I do not know what it is, but I assume that it has to do with the electronic control system.

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snipped-for-privacy@compusmart.ab.ca wrote:

Check here, there are similar procedures perhas for your year/ model: http://www.gminsidenews.com/forums/f53/04-tahoe-c-69926 /

I don't know - but would initially agree with you - the 07's as I recall don't use vacuum for cruise.
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