I posted this in the new user area earlier but not sure if that was correct so I am posting here also. I hope its OK.
I am new to jags. I love the way this car looks and drives but the lights are driving me nuts. The right rear stop light wont work. When the brake is applied the light blinks for a split second but does not stay lit. The module clicks but does not stay up. I replaced the rr brake module to no avail. When flashers are turned on the bulbs flash as they should (same bulbs as brake light). How do I troubleshoot this problem?What actually turns the brake module on for brake lights. Also I dont know if it is connected but the right front blinker does not work (blinker or flasher). I can open up the light module and push in the relay on the pcb and it works so its not a wire issue from the module to lamp. The module does not click like the left one does. Do I have grnd issues and if so where should I look.. PLEASE HELP!!! Thanks.

 

My XJ40 experience is zero but a bad ground does seem like a plausible root cause. It's a good idea to check-clean-tighten them on general principles anyway.

Here's a good XJ40 wiring diagram. You can select the proper section and the location of grounds will be described

http://www.captainjaguarscathouse.co...ec%20Guide.pdf

Cheers
DD

 

Hi,

Don't often hear about this problem with the later XJ40's , but it sounds like you have a one or two modules that need to have some of the interior solder points reworked,

It is a common problem with the earlier XJ40's (88/89 in particular), but you never know. Not sure of your vehicles history and prior ownership, but it could be possible some of the components have been switched out before you had the vehicle. Take a look at the part number printed on the casing of the module, typical part number start with three alpha characters follow by 3 or 4 numerical digits.

If your components are some of the earlier part numbers, the solder points inside get corroded and the solder fails and needs to be re-worked with fresh solder. It's an easy task and obviously you have opened them already. The modules will "sound" okay (clicks) but not perform they're functions properly with bad solder points.

Go here to check your parts against what is proper for your VIN (know your VIN#, it's important to getting help and buying parts) :

Lighting Control Module - Parts For XJ6 (2.9, 3.2, 3.6, 4.0) from (V)500001 to (V)667828 | Jaguar Classic Parts UK

Good luck, if you have more questions, post up.

 

I found the problem. It is the right front headlight module. Thanks for the help.