05 gmc ac/heat

[thevoice48]

I'm having A/C problems on a 05 crew cab. A few weeks ago while driving on about a 100 degree day it was blowing cold air fine and then all of a sudden it starts blasting hot air like the heater had been switched onI would just kill the engine and crank it back up and it would start blowing cold. It's only on driver side that dose it can anyone help

 

[blustrk]

Did you ever solve this problem? I had what started out to be the same thing: HVAC would occasionally spontaneously start blowing full hot when AC was on. Stopping and turning off ignition would correct this until next sporadic occurrence. Lived with this for a while figuring heater HVAC control replacement would fix it. Last summer noticed this was no longer occurring, but was hearing occasional series of "ticks" from vicinity of HVAC control On checking, found driver side would not produce heat when set to full heat, although pass side was normal. Replaced HVAC control and since heard no more "ticks", but driver side heat still does not work. Followed what I thought to be the power off reset procedure (possibly did not get it right), but no change.

Any suggestions, anyone??