Window fogging with heater on
I have a 1985 300D Turbo diesel. I live in the cold & rainy Northwest. With the defroster on the windows are clear, however when I switch to any heater setting the windows fog up. The car is not loosing any coolant, there are no water leaks in the car, the carpets are dry. Is this a common problem? Having the defroster fan howling all the time is rather irritating.