Air from a/c only comes out the defroster vents. What would cause this?

Answer by  Doug77 (1433)

Some duct work is vacuum actuated and could have a leak or stuck lever to move the doors. In a manual duct system, the rod may have fallen off the door pivot that moves air up and downward when you move the selector.

Answer by  rookie105 (823)

it could be a problem in the air box as on a damper that is stuck or broken. it could be a vacuum issues, make sure the vacuum lines are hooked up and working to the air box. find the air box and there is a control valve on it with a vacuum line going to it, does it move?