2003 X Type 2.5 AWD. My high mount brake light does not work. I have gone over the fuse diagrams and can't seem to find the right one. Am I missing something obvious?

Steve

 

If the other brake lights work but not the centre brake light, I don't think it's a fuse - I do not think it has a separate fuse. Check the electrical connection (check if the connecting cable is OK and most of all the connector to it.

 

smithseedway, let me see what I can find on my computer. I have the diagrams for your car and will be able to answer your question. The thing is, I am on travel and am not sure if I have the diagrams with me. Going from memory, the 3rd brake light is its own circuit. So, could be the brake switch, could be interconnecting wiring, could be the light mount in the rear window. Let me see what I can find and I will get you an answer in the morning.

 

First of all, get your own access to the electrical diagrams here
JagRepair.com - Jaguar Repair Information Resource

When you open that link, go to near the bottom of the centre column, click on X type
Click on 2003 to open the electrical pages for your Jaguar
Scroll down to the circuit diagrams and find Fig 8.3

On Fig 8.3 you'll see that all three brake lights share a common supply from the brake light switch, but while the left and righthand lights share one ground point, the centre one, not unnaturally has its own.

Note the identity numbers of the grounds, then scroll up to Page 20, near the top, and there you will see a drawing showing the locations of all grounds.

You, or your mechanic, can now can set about checking for voltage and continuity of the whole circuit of the centre brake light and find the cause of the failure.

 

My high mount brake light had a bad solder connection on its circuit board. I suspect that it’s a common problem since the power lead connections to the circuit board are flimsy.
Some say that the entire headliner has to be removed for access. However I found that I could pull down the rear edge of the headliner a few inches, reach in and remove the mounting screws for the light. It was then a simple matter of finding and resoldering the bad power connection.
By the way the light assembly is a group of individual LEDs, no bulbs.