My cars climate control doors don't work. I have just checked the check valve under the bonnet, seems to be fine. Can someone please explain to me the use of the one control lever under the radio? Not sure what it is supposed to do.
I will be checking out other vaccum lines later today. Thanks

 

The slide control is to change the temp of the air from upper vents versus the lower vents.

It's a subtle, fine-tuning adjustment for use after the system has stabilized.

Cheers
DD

 

Have you checked the vacuum manifold?
I have a known good one for cheap.
Steve in Pacifica CA 94044
65o 455-IIIO

 

Firstly Thanks to Doug for my first post. Much appreciated.
Now to Steve. Not too sure where the Vacuum manifold is. I do have good vacuum at the non return valve.
I have a small portion of the dash apart, well right hand side off and the radio out. trying to get a handle on this but looks like the whole suitcase will have to come out.
Cheers

 

After reading lots of posts on the air circulation of my car a 93 4.0 xjs. it sounds like the upper air vent will not open while the defrost/ Demist is active. So I'm trying to get to the back of the right hand heater control switch to see if its vacuum controlled or electric. If anyone has tried this before and can give me some guidance on how to get to the back of the switch? That would be great.
Not sure if this is the correct way to carry on a Thread or not. Sorry if not. Richard

 

The vacuum manifold is a small black brick with nipples sticking out.
Follow the vacuum lines coming from any of the sources or destinations.
Do you have a Mighty Vac or equivalent?
Disconnect the line from the head and put a vacuum on it.
It should hold a vacuum with everything OFF.
Should it show that it's leaking you'll need to trace the lines.

 

Hi Thanks for that. I'm generally better that that. I do indeed have a vacuum tester. I used it yesterday to test the non return valve. Didn't think to put it on the supply line. Sadly just did that. It built up pressure and held. I was able to switch to and from demist setting without hearing anything moving. meaning no flaps cycled at all. My car was sitting for some time prior to my purchase. love to get in there to see what's stuck but no access. Thanks for the memory jog. Richard