My heater/ac was working fine up until today when now it will only blow any air at all through the defroster vents. I havent had time to pull the ac unit out yet and i wont have time tomorrow either but I figured maybe it was a common problem like the trip odometer? Any input would help. Thanks

 

Sounds like you have lost a vacume line.

If the main vac line from the engine to the panel breaks these things are supposed to default to defrost for safety purposes.

I suggest checking out the line under the hood first before you have the joys of tracking it around inside your dash

 

ok i will check that out tomorrow. it does sound logical Thanks

 

After you have determined that you have vacuum. If the problem still exists, take a close look at the Duct Control Valve. It is a common problem for the plastic "TIT" to break off (red arrow).

Sincerely,
Kurt

 

The control valve itself is also prone to leaking. Either way, stick your ear as close as possible to the HVAC controls and listen for a leak.

JamesC