1988 XJSC V-12 Mfg. 11-1987 LHD Automatic:

The advent of cold weather has unearthed a heater problem in our car

The wiring for the micro switches of our HVAC box in our Jag has been destroyed by a previous owner. Wires cut, missing vacuum solenoids and unknown other missing parts. I do not know which Delanair I have.

I found a complete HVAC box assembly on ebay that looked exactly like mine. All of the micro switches were present and no linkages. Everything was electronic just as I have. The donor car is supposedly a ...

1987 XJS V-12 Mfg. 5-1987 LHD Automatic:

I figured rather than R & R the box, I'd just use the outer bits that i was missing. Things were going at a great pace UNTIL I got to the controls for the Temp and the Fan. My controls are completely different.

My Temp control looks like this ....
https://www.flickr.com/photos/shanec...n/photostream/

While the one from the donor car looks like this ...
https://www.flickr.com/photos/shanec...n/photostream/

My Fan Speed switch ....
https://www.flickr.com/photos/shanec...n/photostream/

Donor Car Fan Speed Switch ....
https://www.flickr.com/photos/shanec...n/photostream/

The donor cars' HVAC box also had this on the side of the box that the wiring plugged into that my car didn't. It also looks like there should be three matching long white plugs that go into it from the harness which I don't have.

https://www.flickr.com/photos/shanec...n/photostream/

My wiring was cut up so bad that there was no chance at all of splicing the wiring.

The (what I assume to be), power plug that runs up from the center console looks like an exact match to the one that came with the donor car box. On my car, they wired the 3 brown-Whites together, cut the black and white clear out but left the thin green wire.

Another strange thing about this is that the Temp control switch from the donor car plugs straight into one of the phantom plugs in MY harness. Same gauge, same colors, same plug. However, again, the Fan Speed switch is completely different along with the wiring. The heavy gauge Purple feeds the Temp Switch while the Red, Green, Yellow and Blue go out of sight behind the Defroster vents and the right motor housing.

I would appreciate any help i can get. This is my daily driver and finally got a break in the weather to try to get some heat and i really don't want to take the dash apart again any time soon LOL.

Like to know if I can make this work, what do i have, MK 2 or MK3 and any suggestions you could offer. Thanks, ~Shane

 

The donor car has the Mk III for sure and your car should as well....as it actually started being used late in calendar year 1986.

My gut feeling is that someone before you has tried to mix Mk II and Mk III parts.

In the pic of the donor car system do you see that module with about a 30 wire connector? Looks sorta like a grand piano? That's the climate control ECU...the entire brain of the system. If your car is missing that part I don't know what to say. That's what controls to flap motors and such.

Maybe someone was using MK II (or some other?) switches in an attempt to defeat the 'automatic' function and turn it into a more ordinary 'manual control' heater and a/c system? As part of that they removed the climate control ECU?

I don't know how to help you except to say take everything off the donor car and put it on your car. I difficult enough getting these systems to work right even *without* mystery parts, cut wires, parts removed, etc.

Cheers
DD

 

Thanks for he reply Doug. Doesn't sound like good news for me. I got the unit from eBay so I guess I'm out that $350 since I don't have the car for the rest of the parts. Guess I'll try to stick the heat on since the micro servos aren't hooked up anyway once I get the right combination figured out and deal with the rest of it again in the Spring.

I was thinking of switching out the harness to the micro servos and ECU from the donor car to mine since I'm already in there but still no plug from the harness to the ECU or even a hint that one ever existed. Just leave my fan switch as it is should get me through the winter ... I hope

 

Here's some MK III infor that might help, if you don't already hve it. There's a wiring diagram among other things

Cheers
DD

 

Shane,

I've moved your question from General Tech Help to XJS forum. More XJS owners will see it here.

Graham

 

New development this morning. I tried the temp switch Push-Pull and the one in my car does. Messed up thing is, so does the one from the donor car! I finally got a good pic of the label on the box in my car. Both the Delanair Code 02000671 and the Customer Code CBC-4444 are exactly alike. Still don't understand why my controls are different unless it's like Doug said, someone tried to mix the two or do away with it completely. I've taken many pics of this nightmare on my flicker acct at.. https://www.flickr.com/photos/shaneclara/15860764635/