don't know what is wrong with it it still blows air out of the defrost ports but not the ports that are facing the driver and passenger the switch still will shut off the blower motor just won't change over from defrost?

thanks

 

you either have a broken vacuum line or the line has come loose from the vacuum pump. one place to look is right under the drivers side battery at the cruise control servo, they are real bad about leaking battery acid down there and eating a hole in the vacuum hose.

 

from which battery? left or right?

mine not working, but I hope its only a split hose.

evacuate and recharge at the moment all seems well. but time will tell.

-dkenny

 

My truck did the same thing. I had an open vacuum fitting in the line where it crossed over the engine compartment, however your problem could be anywhere along the line. I couldn't find a disconnected line anywhere that went to it so I just folded a piece of duct tape over it and it's been fine ever since. I believe the ventilation systems defaults into the defrost mode for safety reasons.

 

vaccum line just had come off of a fitting thanks for all your help!