I have to turn my ac on and put the designator vent into windshield position to defrost my windshield. The car gets so cold - does this have to do with moisture inside the car - say in the seat upholstery? Any suggestions?
I assume the blower is working ok and if the heater works ok inside, say for the feet position, then it sounds like the vent door for the defrost postion isn’t working correctly. If you smell coolant inside the car then the heater core may be leaking and causing excessive moisture inside the car.
The blower does work fine and the heater works ok inside. I don’t smell anything unusual in the car. Does your diagnosis of “vent door for the defrost position isn’t working correctly” a stand alone diagnosis, or does moisture also have to be present inside the car to cause the problem?
When using the defrost, the a/c compressor is supposed to be in operation for evaporation purposes. Sounds like compressor is not operating in the defrost position. Nothing really pops in my mind as to what could cause this. If it was a fuse I would not think it would work in tha a/c position. Maybe a recirc door motor, but hard to diagnose here. Probably need a pro to check.