TaylorLG

I found what I was looking for

Does anyone know where I could find instruction on how to remove dash?

I know the hvac directional system works on vacuum and I have already checked the vacuum lines going from the engine compartment to the firewall and it is good. I have read that I have to remove dash to trace the vacuum line from the firewall into the cab.

My father, original owner, was told years ago it was probably "some diaphram" behind the dash that is bad and that the part is not expensive, just the labor.

I can get to a bunch of different vacuum diaphrams under the dash that open and close vent doors, they are not getting any vacuum and I can't follow their lines from underneath to the fire wall.

CCKen

I wouldn't remove the dash at this point but you may want to access the back of the AC/Heater climate control panel to see if any vacuum lines are disconnected there. (see pics)


Climate Control Vacuum schematic - for '88 XJ:



.
Back of Climate Control Panel showing vacuum tubes (cut off):





There's a Youtube video showing how to get at the heater core for a '95 XJ. It's a 3 part vid. One part shows how to get at the climate control panel.

CCKen

Before blowing anything apart you may want to see if the Recirc Air door actuator is working. If it works the vacuum source from the engine to the vacuum selector on the climate control panel switch is intact.


Remove the blower resistor block kick panel.





Start the engine, the move the climate control selector to "MAX" air conditioning, then to "NORM", then back to MAX. If the Recirc air door actuator is opening and closing the Recirc Air door the source vacuum is intact, if not there may be a break in the vacuum line. See schematic in previous post.


Recirc Air door actuator:

TaylorLG

Thanks!! I am familiar with that door. And while the engine was running. Moving the control from max to norm didn't move that door. I disconnect the line to that diaphragm and no vacuum through that line. I tried following that line and it goes up under the dash. On the opposite side of the controls are 3 other diaphragms that have no vacuum and those lines go further up behind the dash that I can't get to.

CCKen

Looks like there's no vacuum getting to the selector switch (behind the climate control panel) or the switch is bad.


Here's a 1988 AC Vacuum Schematic. See if it matches yours (round connector at the switch).