I am having problems with HVAC, like thousands of Ford owners. Not just Mustangs are affected but other models too, like the F-150. Upon turning the ignition on, I hear the familiar clicking noise of a broken blend door actuator. Not just one, there are four of them. I replaced one blend-door motor, the one you can reach from the glove box opening. I did not see any change, still clicking. It seems, that FORD could not or would not fix those HVAC problems, because the next gen. Stangs still have the same issues.
Now I discoverd another weird problem. Each time I stop the car and turn off the engine, then drive again, the cabin heater comes on by itself, full blast. The control **** is fully CCW on COLD. Driving for a while will slowly turn off the heat. That drives me nuts.
It is a shame, that FORD, a global car manufacturer with long history can not figure out how to design and manufacture an dependable HVAC control system. In the '90 they used vacumm for the controls. Did not work either. Only when they used steel cables back in the '80 it worked somewhat. I hear, that Ford dealer will charge somewhere $600-1000 for the HVAC repair. Gulp!
I have a new slogan: Ford will be Ford