I have a 2004 f250 4x4 that I purchased in December 2010. When I tried to turn the a/c on today it would only come out through the defrost vents on the windshield instead of the vents. I changed the accentorator (?) in the a/c unit and it did nothing but the air is blowing full force and cold but just through the defrost vents. Any suggestions? Thanks for your help.

 

There is a vacuum leak in the system somewhere. The system defaults to the defroster when vacuum is not in the right place. I can not tell you exactly where, but find the vacuum cannister and follow it to the inside of the truck. You will find it.

 

Thank you so much for the advice. I will give it a try and see what I can find. I appreciate your help!