Where to go from here is now the question.

Allright. Checked pressure with engine running and got a good pressure of about 25 -20

I unhooked the tank line and checked it there. Where the main vacuum line and the y come toether and then it goes into the firewall. got great pressure.

Cheked by swithching modes with engine running and there was no loss in pressure.

Im wondering why I don't here the switch sound when I change the mode to dash vents. I hear the switch when I go from all other spots but that one.

Hot

I beleive the acuators can go bad. Did you say you have vacuum at the actuator that is not working?

Im not sure I have checked all vacuum lines that I can check without taking the hvac out of the dash. '
However I did notice that when I switch from say dash ti center vents I hear no "switch sound like the other levels . Does that make sense.

I dont know how to check the , did you call it an actuator? Heck its real hard to get that out Ive been looking at it and Im not sure Ill be able to.

What'* next, anybody?

** Vacuum every where as far as I can tell. All lines tested positive and held. **only thing I don't know how to do is check all the lines under the dash. I am not sure about taking that HVAV black thing that has the vacuum lines going to it off,,, I SCARED..

I borrowed this diagram from another thread, and my "hissing" is coming from the connection where the purple line goes into the "vacuum harness connector". I am now with james. Where do we go from here? Anyone? Anyone? Bueller? Bueller?

Nice job Echo..
Looks like there are two nuts to get that off. Randman said once you get the nuts off that there is a seal. We might have to finagle our way into this. I think Im going to attempt to un attach it and then see what is in side. I guess Ill have to get some kind of voltage tester to see if the airmix actuator thing is working. Im just going to dig in what the Heckel. Someone say a prayer.It could get ugly. I don't cuss often but I feel once I start that I might use a choice word or ten.

Does 5 hook into the back of four? That could be a tight area.

I wonder what would happen if we took the programer connecter loose and reattached it?

I know what you mean about wanting to tear into this thing. I am ready, too.

Yes, 5 does connect to the back of 4 and it is tight. Randman referenced the connection in this thread where I found the diagram. http://www.bonnevilleclub.com/forum/...highlight=hvac
Also, bolts 8 and connection (7) need to be removed. Hopefully that is it, then drop the sucker. Also, the nut on the bolt in the center of the vacuum connector may allow me to remove the connector only. Maybe, I have a loose hose or a broken connection. I am with you in spirit since I can't be there myself. Good luck.

The air mix actuator (4) has nothing to do with air flow distribution. It either allows or blocks air from passing through the heater core thus controlling the temp of the air. This is not an easy part to get at and I really don't recommend exploring in that direction if you don't have a temp control problem.

From what is posted here already, your problem does not appear to be a vacuum source or tank. Your vacuum gauge makes that pretty clear. So now, we move down the line to the programmer (6). Purple in the input and the other colors are outputs to the air diverters (diaphragms) I'm not sure which ones are which though. If you are successful in removing the vacuum line connector as it enters the programmer, you can test the air diverters by fashioning a jumper line from the purple line to the others. This will require some small vacuum line and connectors from the auto parts store. Again listen for a hissing sound as you jump to the individual lines. There'* at least one diverter that you can physically see without too much trouble. It'* located above and to the left of the gas pedal. the others will require some contortion. When vacuum is applied and removed, you should see the arm move one way and then the other.