Temperature control
 

I have a 01 monte carlo. The temperature is stuck on heat. When I turn knob to blue for cold it stays hot. Do I have to replace temp control switch or check out somethingelse. If I do have to repl switch, how hard is it, and how do I do it. I've already taken dash apart to get instrument panel out to replace lights out a few years ago.

the temp door motor could be faulty or the door itself could be stuck in the hot position if it hasn't moved since its been cold out. the hvac control heads are pretty reliable in the W-body cars.