Still working on a friend’s 1988 XJ6 and I have a “bulb failure” indication on the dash and the right rear turnsignal light is not flashing as expected.
The left turnsignal (both front and rear) and the front right turnsignal indicators function fine but the right rear one only flashes once in a while either with the hazard lamps or activating it via the actual turnsignal switch.
I have replaced the bulbs in an effort to solve this but no luck so far.
Any suggestions?

 

My first post as I am chasing similar issues on mine.

I did a full LED upgrade and have no flashing, I intend on going after the flasher relay and changing it for an LED flasher. It resolves the issues on GM stuff Im used to so I imagine it will trick the old Jag.

Anyways, you should add a new flasher for your signal lamps they should speed up. I am unsure of the location but I have my interior taken apart and I beleive they are up in the passenger foot well

 

I suspect you have the dreaded Jaguar dry solder connection- probably close by the bulb on that controller panel. Much has been written on the topic, but it comes down to running a hot soldering gun over the affected area possibly with a bit of solder on the tip of it.

 

A suggestion was made over on the Jag-Lovers forum that I swap the bulb failure modules from side to side to see if the problem followed the module or not.

I did swap the bulb failure modules this evening and the failure followed the module rather than staying on the original side. So my next job is to open up that troublesome module to look for bad solder joints.

BTW, I did this with the ABS overvoltage protection relay and by reflowing three or four solder joints I was able to make the relay actually work and now the ABS warning no longer displays on the dash after the engine is started.

 

Hi RoseCityTinting,

Welcome to the Jaguar Forums! It's great to have you with us!

As far as I can recall, there is no conventional flasher module on an XJ40. The turn signals are controlled instead by the Central Microprocessor (CPU) by way of the four Bulb Failure Modules (BFMs). If you'll let us know the year of your XJ40, I'll post a link to the Electrical Guide for your car.

Cheers,

Don