Ever since I got my '85 XJ6 in April the Climate Control has done nothing. I don't mean it doesn't blow cold enough; I mean all it will do is blow air out the defrost vents, period. I put off tackling it for so long because I feared it would be a huge kerfuffle. But, now that I don't really need A/C anymore, I took the plunge.

As soon as I took off the RH console side panel I found that the vacuum feed line was disconnected. I reconnected it and tested for vacuum leaks and found none. Could it be that simple?

No.

Now the fan won't come on anymore. I made sure the car was warmed up. I even tried disconnecting the vacuum again. Nothing, and the fan was the only thing that worked before. I can hear various stirrings inside the dash when I move the controls so at least parts of the vacuum controlled system are working.

So here's my question: is there anything electrical that would have been off as long as the vacuum was disconnected and now has switched on and caused a fuse to blow?

Thanks,

-mB

 

could it be that you disturbed some electrical connector when you reconnected the vacuum line?

retrace your steps. Where exactly was the vacuum feed disconnected and reconnected? Can you post a picture?

the "stirrings" or "clicking" sounds that you hear must be the SERVO trying to open and close flaps. It sounds like that. The SERVO is like a miniature crankshaft.

Look at all the rod linkages to see if you see any adjusting "stops" that are lose.

The "default" fallback of the system when there is a vacuum or another issue, is the Defrost, so it was doing what it was designed to do. It happens the same way with Ford cars.

the picture below shows the linkage rods, you can see the Stops at the bottom.

the PDF file contains lots of information about vacuum and electricals of the Mark 2 Climate system in the XJ-6. Download it.

 

Look up my old thread called "A/C Dazed and confused" or something like that. It isn't exactly the same problem as yours, but similar. It contains all of the information that you are going to get from the Guru's over the next couple of days, so worth a read. I will post the link if I can find out how.

 

https://www.jaguarforums.com/forum/x...ighlight=dazed

 

Thanks to Richard for that link. I suspect he's right and that covers it all.

I have a pretty good troubleshooting guide I found at Delanair Mark II Automatic Climate Control

Today I managed to exonerate the fans and the main fan relay. I found that applying 12V to the relay terminal where the B/W wire attached causes the relay to engage and the fans to come on.

I checked the main fuse for the AC blowers, and the in-line fuse to the AC clutch and they are good. I may have checked the in-line fuse for the amp, but the wire colors were different, brown when the diagram says black. But that fuse was good. And the wipers work, so that fuse must be good.

I found there was no power either side of that 10 amp inline fuse for the AC compressor clutch (ignition on, knob set to defrost).

That's as far as I got today.

It's very weird that the fan worked fine until I connected the vacuum hose. But while I can find a couple vacuum switches controlled by electricity I find no electrical switches controlled by vacuum. So either I jostled something when I took the RH console side off or it's just a coincidence. Imagine, having a weird electrical problem in a 30 year old Jaguar.

Oh, and since Jose asked for it, I enclose a picture of the vacuum hose I reconnected. In the picture I point to the joint with a screwdriver.

Thanks,

-mB

 

yes I see it, thanks.

doesn't look like anything might have been disturbed electrically. Must have been a coincidence, since Vacuum opens the different Flaps, it doesn't turn on / off the blower motors.

 

Today we took Esme for a drive up into the mountains to see where the fall colors had recently been. About 20 miles outside of town the A/C fans started working.

I don't know why they suddenly started working. But on the other hand I don't know why they suddenly stopped working. So I figure it comes out even.

-mB

 

a lose fuse or a lose fuse connector / contact behind the fuse box. Typical on-off-on-off when these cars have an intermittent fuse contact, must be something very silly, start with the fuse box, the one to the right of where you fixed the vacuum line. Otherwise check the white fuse holder above the vent in the picture.