I have a '91 Cougar that has intermittent heat in which I already had the thermostat changed but does the same thing.
What happens is that when I go to defrost the car in the morning, no heat will come out and the temperature gauge goes almost 3/4 up without going in the red zone, and sits there for a while and still no heat. Then the gauge goes down and heat comes out. This happens on and off. I had the thermostat changed and it worked for about 1000 miles and now it is doing the same thing.
Any Ideas Thanks in advance