I was out driving my 1994 XJ12 and a buddy told me that my brake lights were not working. When I got home I inspected them and found that the work intermittently. Example five pumps of the pedal may be fine and then 3 or four nothing on any bulbs, etc.

I inspected the bulbs and they all had dark spots, 3 each number 1156 on each assembly. The book shows 7506 to be correct so I replaced them with the right ones, (Look the same but slightly different wattage and amperage).

Still the same issue. I will see if I can fit down on the floorboard and inspect and test the stop light switch, (Maybe some crud causing the problem). Otherwise, I know that there are unique computer functions relating to the lights and what no but have to assume, which I know is not always wise to do, that the stop light function is or should be independent of rest of system for safety reasons.

Thoughts, ideas, ways to make the pain go away, free beer?

Thanks, Scott

 

Hi Scott:
So, I'm jumping into water that is really outside my depth, but since nobody else has yet responded…

I had to replace the stop light switch on the '94 (XJ6) I used to own because it also controlled the shift lever release. I noticed that when it wasn't allowing me to shift out of park, neither were the rear lights illuminating. I'm only guessing that it's the same thing on your XJ12, perhaps even the same part. It wasn't expensive as I recall, but holy cow do you have to contort yourself to reach it - basically bending yourself in half, the wrong way (on your back), up behind the steering column.

I'm sure there are all sorts of electrical connections that should probably be checked with ohmmeters, etc. But considering that I don't even understand the sentence I just wrote, I'm not the one to say…

Good luck!
Scott