I replaced the stat in my '97 Ford F150 - 4.6L. The heater worked perfectly the next morning. It blew nothing but cold air that evening and always since. Other than possibly having the wrong stat or a defective one is there any other reason I would have this problem not withstanding a clogged heater core (which it's not). By the way I tried to donate to your cause but the link didn't work (some kind of error).
have the same problem?
Monday, February 5th, 2007 AT 7:05 PM