My 2003 f150 blows the a/c out the defrost when you give it gas when you let of the gas it goes back to the pannel.
I belive it is a vacume leak some where, I looked under hood, behind battery, and traced out everything I could find under the hood up to the firewall, where else should I check, I have the three ***** you turn for control is there something that fails where they are??
thanks for the info, I found the vacume leak right behind the battery, right where yall said it would be. A small section of solid line was all melted, I guess this happened when I left my battery cover off for a few months(this was stupid all it did was cas stuff to rust and corrode quickly from the extra battery gasses. Cover back on and leak fixed.