Stumped...again (ac vents)

[MR2CHIPO]

For my monthly TR ordeal I offer you the following :redface: The a/c is blowing out of the default floor and defrost vents. After numerous searches here I was able to confirm vacuum at the purple line behind the glovebox. This should mean that underhood lines are working properly, right? Then I figured I would replace the small valve behind the controller as this fixed this problem for many here, but still nothing. I'm hoping someone here can guide me in the right direction. Worked fine before car sat for 2 years while engine got redone.

 

[novaderrik]

does the air door itself move? they can get jammed up when something falls into the heater box (i pulled a pencil out of the door in my 97 Cavalier) or if a mouse builds a nest in there..

 

[Waco84GN]

Can you hear a vac leak?

When you command different vents to open do you hear vac leaks inside the car? Could be the old brittle vacuum lines falling apart.

Very rarely do the vent actuator diaphragms mess up and leak but its a possibility.

Jerry jr.

 

[MR2CHIPO]

I don't hear any leaks when changing from one control position to another. Just to verify, with the heater bypassed, is the gray under hood hard line supposed to be capped off? I'll be tackling this again 2morrow and let you guys know what the solution is....if I find it

 

[NarcGN]

There is a 3 or 5 way control port behind the actual AC and heat panel on the dash. NOS4GN had it pretty cheap. Mine blew last year.

 

[MR2CHIPO]

Just replaced the control valve behind panel, still no change. So far I have replace both air control valves and confirmed vacuum at purple line behind glove box. Removed blower motor and stuck my hand in there to confirm nothing had stuck its way in there. I'll bet it will end up being something stupid, but right now I'm out of ideas