I have a '97 f-150 . Just this last week after driving to work with my defroster on, I started to drive home, I turned the selector back to A/C from the defrost position, and nothing changed. The blower still works, but will only come out at the windshield. The switch will turn off the blower, but will not change to any other position, such as floor, panel, A/C etc. If I turn it to A/C or Max A/C, it will blow cold air, but at the windshiield. Any Thoughts?

Thanks Drew

 

Look under the hood on the right side(near RF tire) of the firewall.. you should see a vacuum check valve.. Make sure it hasn't come loose and if it hasn't.. Start checking the lines ,, Possible that they might have a dry rotted or cracked place in them..


Good Luck!!

FordMasterTech