Erratic electrics '93 facelift 4.0 convertible RHD

[IanHolliday]

Hi everyone,
Here are the symptoms of my car's wierd electric behaviour:-
no interior lights on courtesy door switch (all function ok manually)
passenger door mirror switch randomly moves passenger seat, occasionally moves the mirror!
engine runs with no problem but in use it sounds like the passenger seat motor is operating (without moving the seat!)
the boot lock has not worked with the central locking for a long time but suddenly it started to work for a while, now U/S again

I wonder if all this wierdness is caused by a weak earth connection? If you agree, could you please tell me where the most relevant one is please? I cannot find any earth point location info in the workshop manual.
Any other ideas would be much appreciated. It would be nice to sort it out during the winter lay-up ready for next year's motoring joy!
Thanks in anticipation, Ian H (Derbyshire, England

[ptjs1]

Ian,

I'm not sure which workshop manual you have, but the Jaguar workshop manual electrical section details the locations of each of the earth terminals on each of the circuit pages.

However, the erratic behaviour that you have described, all seems to emanate from the left hand door, therefore one would assume that the problem may lie in damage to the wiring that passes through from the A-post into the door. Perhaps a chafed wire which is causing one or more of the circuits to take live to earth.

I would start by disconnecting the battery and then carefully checking where the wires pass through from the A-post to the door.

Good luck

Paul

[IanHolliday]

Thank you for your thoughts, Paul. I will check as you suggested because you are right in your observation, all the problems seem to involve the passenger door - I guess it sometimes needs someone to point out the obvious!!
I have the workshop manual on a DVD and although I can see various earth points within the circuit diagrams I cannot see any detail as to where they are actually located in the car.
Kind regards,
Ian H

[ptjs1]

Hi Ian,

Good luck with your investigations!

As regards the earth points, see below typical pages from the wiring diagrams, where the detail page identifies the approx locations of the earth points. Hope that helps.

Paul

[IanHolliday]

Thank you again,Paul. Your version of the workshop manual is different to mine and shows those ground points that I don't have. Your copy of them you posted is rather too small to see and enlarging it becomes too blurred to read clearly although I can just make out the improved data. Is there any way you can send me a better copy? Maybe direct to my email - if you send me a private message I can then tell you my email address.
Cheers, Ian

[ptjs1]

Ian,

Just use the online resource at http://jagrepair.com/

Pick "XJS" in the Electrical Section, then pick the 1994 4.0 Electrical in the top section. (Most UK "1993" cars are 1994 MY. Assume you have big bumpers? If your VIN is pre-188105, then use the 1993 Electrical one.)

Cheers

Paul

[IanHolliday]

Wonderful! Thanks again, Paul. A resource a had not previously been aware of.
Information all now ready for when conditions are suitable for working on the car
Cheers, Ian