I have been having an issue with my dash vents not working. Only the floor and defroster works by default. I replaced the check valve and a cracked line running from the valve to the vacuum canister. I also used a mityvac to test all three lines. (all from check valve to manifold, to canister, and to dash controls they all seemed to hold a vacuum. I am now stumped and don’t know where to look. Is there anything else I can check, getting a little frustrated and about ready to take it somewhere and pay the 70 bucks to have it diagnosed. Hope someone has some ideas.

Thanks miles

 

So you can remove the vacuum line at the intake manifold, pump it up to create ~20" of vacuum and it holds?

Do you hear any hissing going on at the mode selector on the dash when you change modes? Maybe the problem is there.

 

I second that, I had to remove the control from the dash and hook up the mityvac to each actuator's hose individually until I found mine. Do you know the color code?

 

Mine cracked the replacement valve in about a week, I RTV'd the original and it's still together since last summer. May want to check the valve again.

 

the valve is fine, I always check that first since i know its an easy fix. The line at the manifold holds. I pull it off and then stuck the vac on that end and it held fine. I dont think i hear anything when i switch the controls. I guess this would be a test when the motor is on right? I will check for this today when i run to the store. How hard is it to get into the dash to check those lines? Sounds like a pain in the a**

miles

 

You only have to get to the control. From there you can test the incoming line for vacuum and apply vacuum by hand to the 4 lines to test for leaks to each individual actuator. If your control makes no vacuum noise when switching from function to function, then you have lost vacuum from the engine compartment to the controls.

That is easy to test from the controller. I think I had to remove the kick panel driver side and pull the glove box door down to get the center bezel off.

 

i hear a swooshing sound is the best i can describe when changing the **** quickly. I think that is normal. can you give me a detailed list of what or how to disassemble to get to that control. It would be appreciated.