2002 Tahoe freezing us out

[ultraviolet]

I've got a 2002 Tahoe LT (auto climate control option) with about 115k that has some sort of ac issue.

Starting rarely last winter, the ac would seem to get stuck on - the ac would turn on because the car was driving in direct sunlight and then it would fail to turn off and begin to freeze us out. The speed of the blower when the ac kicked on could only be adjusted upwards - it wouldn't ever get slower. You could turn it off completely, but then turning it back on would get blasting cold air. Even if you turned up the heat all the way - no heat, just freezing air. Only when the cars ignition was turned off and turned back on would it fix itself. DH thinks (I haven't had time to test it myself, since he just "discovered" it this week) that the blower control function returns if you switch it to re-circulation from fresh air and then back to fresh air.

The rear ac doesn't have the same issue and it's never happened when warm air is required - only colder air.

Based on what I could find, I was thinking that it was a faulty blower control module. However, it seems like most who replace that have NO control, at any point and it seems like they get hot air, not cold air. Anyone have any ideas or should I just go ahead and try the blower control module replacement?

[jonnik]

There must be some sort of sensor that monitors the cabin temp and adjusts to the set temp. You might see if you can find and replace this sensor.

[MT-2500]

Originally Posted by ultraviolet

I've got a 2002 Tahoe LT (auto climate control option) with about 115k that has some sort of ac issue.

Starting rarely last winter, the ac would seem to get stuck on - the ac would turn on because the car was driving in direct sunlight and then it would fail to turn off and begin to freeze us out. The speed of the blower when the ac kicked on could only be adjusted upwards - it wouldn't ever get slower. You could turn it off completely, but then turning it back on would get blasting cold air. Even if you turned up the heat all the way - no heat, just freezing air. Only when the cars ignition was turned off and turned back on would it fix itself. DH thinks (I haven't had time to test it myself, since he just "discovered" it this week) that the blower control function returns if you switch it to re-circulation from fresh air and then back to fresh air.

The rear ac doesn't have the same issue and it's never happened when warm air is required - only colder air.

Based on what I could find, I was thinking that it was a faulty blower control module. However, it seems like most who replace that have NO control, at any point and it seems like they get hot air, not cold air. Anyone have any ideas or should I just go ahead and try the blower control module replacement?

It is controled by the body computer.
You need to get it on a AC/body capable scanner and check operation and codes.
Post back Body PC code no.
Also pull the fuses or do a battery disconnect to reset and recalibrate it
MT