Jmccreary

I got my ac charged last night on the 80 vette. Cold air blows good from the lower vents, but no air blows from the upper and side vents. Is this normal or should air be coming from all vents? If it is what could be causing the problem.

Thanks
John

Ganey

John

This should do it.

FAST FIX by GANEY
On at least later C3 the problem is that heater is the default position (no vac. or vac. leak) due to being designed in the north. Vent should be default. Very safe bet the problem is 1 OR 2:
1) The vac. line from engine is damaged from heat - a small plastic tube that goes in below the hood theft switch into wiper valley. Replacing most of engine side w/ hose will fix. OR
2) The vac. switch itself is not switching due to vac. leak as the usually plastic rivet is not holding the 2 main switch parts together well. Besides replacing, it is also possible to tighten this &/or lube w/ a thin layer of white lithium grease or vasoline to fix.
3) If you have a heater, the hose to heater hose valve underhood probably also needs replacing. Block w/o heater.

PS The design problem comment is not intended to be offensive to any of our northern friends. :cool:

Tom73

Also check the under dash ducting seals, could be that all the air is leaking out under the dash.

tom...

SmokinL82

i just got done working on mine.....took everything apart :banghead: it had vac from the eng, but it wasn't opening the upper vent door. so I plugged the vac in to the upper vent servo. it worked. so i just bought a y and hooked it in. It must be in the switch. Oh well, i got air now :thumbs:

It could be the servo or door is stuck ???? or vac lines crushed