Climate Control Problems after car stereo install

I recently took my '08 Tahoe Z71 back to Best Buy for them to fix an intermittant power issue in my stereo. They took the radio out, found the problem and put it all back together. I normally drive with the climate control on "Auto" between 68 and 70 degrees. Well, after I got the truck back, it blows ice cold air and I have to raise it to 80 degrees before it'll calm down. This morning, I got into the truck and the climate control was running perfect at 70 degrees up until about 15 minutes of driving. Then the air kicked in again and I had to raise it back up to 80 degrees. Could they have moved the thermostat for the climate control system by mistake? Where is the temperature sensor for the climate control?

My gut feeling is that the sensor dropped behind the radio and it's reading the heat from behind the head-unit and kicking in the air conditioner.

Any help is much appreciated

I recently took my '08 Tahoe Z71 back to Best Buy for them to fix an intermittant power issue in my stereo. They took the radio out, found the problem and put it all back together. I normally drive with the climate control on "Auto" between 68 and 70 degrees. Well, after I got the truck back, it blows ice cold air and I have to raise it to 80 degrees before it'll calm down. This morning, I got into the truck and the climate control was running perfect at 70 degrees up until about 15 minutes of driving. Then the air kicked in again and I had to raise it back up to 80 degrees. Could they have moved the thermostat for the climate control system by mistake? Where is the temperature sensor for the climate control?

My gut feeling is that the sensor dropped behind the radio and it's reading the heat from behind the head-unit and kicking in the air conditioner.

Any help is much appreciated

See if there is a recalibrate procedure for it.
Factory repair manual or http://www.alldata.com/products/diy/index.htm
Also check for a repair flow chart for that problem.

If so run it.
Other wise you will need a HAVC capable scanner to find the problem.
If any HAVC codes post back codes.