PLEASE HELP: 2001 Yucon HEAT will not turn off

Hi,

I have a 2001 Yucon XL and the heater will not turn off no matter where the settings are. You can place the heater setting in the blue (cool) and turn the A/C on (the light will light up) but still blow hot. As we drove home from Chicago yesterday with one rear window open, it started to blow cold by itself after two hours of blowing hot.

I have no clue what is going on and am certain that it would cost a fortune at a dealer. Does anyone have an idea? Thanks for any help/suggestons.

I have the same problem. Works on in the morning. At night no control over the tem. Just hot. Let me know if you find a solution. I will post something when I tear in to the dash this weekend.

Had a similar problem had blower but no heat and no control over which area i.e. vent,defrost, etc. Had to replace the AC control module. That is the complete control unit for heat, air etc. go to ebay and go to factoryautoparts. They have the switch for $96. Great price also.

Hey guys, I just tore into a A/C control modual on my 95 that has the same issues you are describing. I found a burnt resistor on the board and replaced it. Problem solved for under a buck!