I had a problem with the Instrument cluster illumination in my 1992 XJ40. It stayed always on, only way to switch it off was to disconnect the battery.
I found out that the problem was a shorted transistor on the PCB, it is marked as TR3 on the board.
The transistor type is a ZTX751. Bought a new one from Mouser Electronics for less than a dollar.
Replaced it and the unit now works as it should.
Hope this can be of some help for others with the same issue.

/Anders

 

Hi Anders,

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

Thank you for posting the information on your repair. I'm sure it will help others for years to come!

Please visit the New Member Area - Intro a MUST and post an introduction so we can learn something about you and your Jaguar and give you a proper welcome.

Cheers!

Don