Hi All, I'm new to the forums, so take it easy if I missed something in the search, I'm getting used to where everything is. I've got an 86 USA spec XJS V12 and a 92 USA spec XJ6 Vanden Plas, and love them both.

I've got an unusual problem with my XJS driver side tail light, and I've about pulled my hair out going through wiring diagrams to trace the problem. For some reason, when my left turn signal is on (or the Hazard Lights) All of the tail lights on the driver side flash very dimly. All other lights on the car work properly, and when the brake lights are pressed they work properly. If the lights are on, the Driving light and the signal light alternate flashing. Obviously something is touching that shouldn't be, to make what is essentially a floating ground in series.

I've checked the actual housing, the switches and the light-out modules to no avail. I thought perhaps the Flasher Diode for the left side, but I don't know if it would even have that effect (Or where it is for that matter).

Anybody run into something similar, or have any ideas? Sorry for the book, but I'm at an impass and wanted to see what I might be missing...

 

Sounds like a classic symptom of a bad ground. Clean all your grounds.

 

Thanks for the tip! I'll start going through those in the morning. Is there by chance a listing of the grounding locations for the XJS that anyone knows of? I know of a few, but I'm sure there are many many more...

Coming from a 1970 model MG, I know how quirky Lucas wiring can be, but this is a whole different beast with the modules and electronics added in .

Also, thanks to whoever moved this to the correct forum. I wasn't sure which one was preferred for this type of topic.

Cheers!

 

Your best bet is to buy the jaguar DVD for your car. You can buy them from any of the jaguar suppliers, or order them from JDHT.com. I just got a flyer today from Welsh and they have the older part number disc JHM-1114 on sale for $10. Covers up to 1987 XJS. The interface is poor but I have spent the time to sift through the folders on it and organize the material into my own folders. I think there is more info on the version than the current version. If you are a Mac person like me then the interface makes no difference as it is Windows only. You have to manually hunt.

Sned me your email address and I can send a wiring diagram that has all the ground points.

 

I'm not exactly sure how to do a PM (is it available?) but my email is DragonStar2435@gmail.com. Thank you so much for your info, and I'll check out the DVD's for both of the Jags, sounds like they're quite helpful!

 

While you are awaiting the DVDs etc here is a list of those that I can remember I found on my rebuild:

1. Behind each headlight in the nacelle
2. Each side of the radiator top panel that is bolted each side to the wing
3. On the RHS lower chassis rail in the engine bay, below the header tank a big woven earth strap (comes via front subframe from engine sump sandwich plate)
4. On engine top, by ignition amplifier, second one by full load vac switch on RHS intake manifold cabin end
5. In cabin, under the centre console (several)
6. In cabin on the bracing struts each side of the aircon unit
7. In cabin around the instrument nacelle several
8. In boot (trunk) under the ECU/relay area, two or three bolted into the chassis rail top under the carpet
9. Each rear light cluster just on the boot interior side of the nacelle under the carpet backing the nacelle
10. Aerial relay earth in boot RHS tunnel

No doubt there are loads more I have forgotten, like courtesy light earths etc!



May I suggest you are careful to file the connectors to clean shiny metal, and the chassis points they fix to, and then spray the cleaned up bits and area with electrical contact cleaner. Then spray grease over the assembly when tightened up, preferably using a new flat washer and spring washer to help clamp the connectors securely. FWIW, my electrics were all working Ok before the rebuild, but their performance was miles better afterwards.


Greg