Pontiac Repair: front defrost-94 grand am, pontiac grand am, hvac control

Question
Hi Todd,

The front defrost on my girls '94 pontiac wont work. The other vents do though?

It's a 1994 pontiac grand AM SS, V6,automatic, and I think it's a 3.9?

Any suggestions would help enormously!

Thanks

Justin

Answer
Hi Justin.

Well it can be a few things either weak vacccum supply to the HVAC control head. A bad control head, a bad acatuator for the mode door inside the heater box or a stuck door inside the heater box. Without seeing the car and what it's doing those are all the possibilites If the modes will goto floor and to vent . I know you said vent works but if the floor works as well I would lean more to a door sticking or a bad acatuator. Good luck :}