calvin02

On my 2000 F-150 5.4 it just started doing something weird, when I go up this one long hill the AC stops blowing from the panel where I have it set and blows from the defrost vents. When I top the hill it switches back to the dash panel. I am assuming this is some kind of vacuum issue so I checked all the vacuum lines and can't find any loose or worn/cracked.

I don't think it could be related in any way but I just had a new battery installed (the original one lasted 7yrs and 8 mos, not bad!)

calvin02

bump

calvin02

nevermind guys. I found a forum where someone answered my question in about 15 minutes after posting. This one is at 2 weeks and counting. Try ford-trucks.com, it rocks.

thefonz

So why not post your solution here? It may help someone in the future.

krismoore

It is your vac res or lines...easy fix! visit your Ford house or auto store