I just purchased a '12 SH-AWD Tech 6MT with 91k miles and I'm having an issue with the AC system. When the engine is cold, the drivers side blows ~ambient and passengers side cold. However, as the engine and coolant warms up, about 10 minutes, the drivers side blows cold. From my forum research, I've done the HVAC diagnostic and it's not showing any problems which leads me to think it's not a blend door but perhaps low refrigerant. It just seems odd that the drivers side changes from ambient to cold and then stays there. That's with no interaction and the system on auto at 70F. Does the blend door sticking throw a code during the diagnostic cycle? I'm going to get a refrigerant pressure test and recharge the refrigerant just in case, but wanted to get some thoughts on how likely that is to be the culprit and not a blend door.

 

Maybe turn off Auto, set AC is set to LOW and full blast it to confirm temperature is cooling correctly on both sides. I would also change/check the cabin air filter. It almost seems like the Driver and Passenger side climate zooms seems a bit off, maybe click on Sync button.

 

I changed out the cabin filter last weekend. It was pretty nasty. Tested again with auto turned off, set to low and max fan, adjusted temps differently, tried different vent settings and same result. Ambient driver, cold passenger on startup. I'm hopefully going to get the refrigerant checked/recharged this afternoon, so fingers crossed that solves it.

 

sounds like a sticky blend door motor