Does anyone know why my 1999 318 Dodge Ram 1500 will stop blowing air out of the vents and switch to the defroster vents at the windshield when I accelerate? Any ideas where I begin to look for the problem?
Thanks!
Mike

 

Welcome to DF. That is some thing called wild vents and it happens because of a bad check valve or vacuum leak. Do a DF search for "wlid vents" and you can find a lot of information.