A/c Blowing Hot Air

[wilkinsonmark]

I have replaced the control unit and the resistor+harness. The resistor fixed the fan not blowing issue, but the driver side a/c blows hot air randomly. I have seen some discussion on the blend actuator but nothing definitive or instructional. Need some how to advice.

[bac078]

I replaced my blend door actuator that is located under the dash, accessed from the drivers side floor board, just above the gas pedal. My issue was the random hot air (eventually nothing but hot air), and the system defaulted to defrost mode, where it only blew through the defrost vents. So I am not sure if this actuator is your full problem. After I replaced the actuator my hot air and defrost mode issues went away. I would try a system reset first to recalibrate the system and see if that fixes it. After replacing the actuator it is something that had to be done, and before the reset it was still acting goofy. I cant remember exactly how to recalibrate the actuator but a search on here is how I read how to do it. Something weird like take the fuses out, open and shut the drivers door replace the fuses, turn the ignition key on (not starting the engine) for a minute and you will hear the actuator cycle, then start the truck. Here is where I got the recalibration from http://www.gm-trucks.com/forums/index.php?...ibrate+actuator