Newcomer - TX

I suspect a blend door issue or a vacuum issue depending on rpm. There are several good forums here that can help you out so try posting in them. The Super Duty forum is a active one and has experienced people in it: Super Duty And Heavy Duty - Ford Truck Enthusiasts Forums You can also get help in the Heating and Cooling board: Cooling, Heating, Ventilation and A/C - Ford Truck Enthusiasts Forums
And for local information you always have your state chapter: Texas Chapter - Ford Truck Enthusiasts Forums




