A somewhat more challenging problem. My car had its rear end massaged by the bumper of a texting Tundra driver at an intersection a couple years ago. Car was repaired and all was fine, my rt rear brake is out, the other two function as per normal. I've pulled it apart and changed the bulb, checked an rechecked. Based on wiring diagrams (X250-12MY_MP1_SERVICE_LHD.book (jagrepair.com)) and the fuse panels (en_GB (jlrext.com)) it would appear that there is no fuse for only the rt rear brake light and that the purple-orange wire in the harness must be faulty somewhere.

Has anybody suffered this confusion? In the meantime, I'm going to go and take it all apart and quadruple check that it's not the bulb.

 

Could be the connector in the bulb holder. Years ago I had a rear bulb go in an S-type. Bought one from local Jag place. Put it in, no joy. Got the Parts Manager to come out, a little fiddling & presto, it lit. Put old bulb back in & that worked now ! No loose wires I could find & carried on working for next 3 years till I sold it.

 

Good news, bad news. Bad news is I'm dumb and didn't realize there was LED's in the fixture and the LED's have died due to humidity getting into the housing. Good news is I figured it out.

Took both fixtures out and plugged into each side to verify.

Wrecker part ordered.

 

Fantastic !
Glad you got it sorted.
You're not dumb:
Just a thought- even a $10 multimeter would save a lot of time, confusion and angst for future issues such as this !

 

I’ve solved a lot of thousand dollars issues with a ten $$$ multi tool from harbor freight.