LBJ, assuming you are having problems with the driver side air:
http://sparkys-answers.com/2009/09/2...s-hot-air.html
My '05 base model with manual dual zone AC will randomly blow full hot and only reset if the truck is turned off and back on. I have heard that you can take the actuator out, open it up, clean all the contacts inside and regrease it as they become sticky over time, lose contact, and start behaving abnormally. I haven't spent the time to do so, but I think if it isn't "buzzing" or clicking, you may have a shot at it working. In the case of my Tahoe, the actuators start buzzing loudly when the tiny plastic gears begin stripping out. I still haven't tried out my Dorman replacement to see if it works better than the Delco I had been buying. At least it isn't the passenger side, since apparently it is very labor intensive to change.