AC Vents

[batmansbuick]

I've noticed when my AC is on full blast, I've got some air coming out down at the bottom of the dash, right by where the center console meets the lower dash, when all the air should be coming out of the upper vents. Is this a vacuum problem with the vent openings or something? Thanks for any info!

 

[turbofish38]

I'd bet the vacuum selector valve on the back of the control head is broken. NAPA and AutoZone should have them. If not let me know and I'll sell you a GM/Delco one.

 

[scottyb]

Mine had the same issue - some of the air came out of the lower heater vent. Mine was missing most of the foam that seals that flap that closes that vent. If you remove the deflector and look up you can see (some of) the operation of this flap. I cut a piece of roofing foam and glued it to the bottom of the flap and fixed the problem 95%. Small hands are helpful if you don't want to remove the whole damn thing.

turbofish38 is on to a possibility as well. The default position of the heater flap is "open", and vacuum is used to close it when AC is on. Lack of vaccum via a bad selector, bad actuator, or other reason may cause problem.