My two main brake lights stopped working, but the middle one on top of the trunk is still operational. Turn signal and running lights work fine. I also noticed that the hazard lights do not come on when I push the button, don’t know if that’s related. Any help would be greatly appreciated thank you.

- Scott
1992 XJS V12

 

Get a wiring diagram and look for a common point.

BTW, did you check to see if the bulbs are good?

 

Here's the diagram. Nothing common between the hazard flasher and the brake lights. Looks like the only common thing for the brake lights is the bulb failure unit.

 

This is most likely the cause. It was for me. Unfortunately, they're NLA, so you'll need to source a used one, or New, Old stock.

Or you can try and either bypass, or build a custom bulb failure sensor.

 

thanks for the info and bulbs are good

 

The bulb failure relay/unit did the trick. Got it replaced and it’s working as published! Thanks for the help.

Scott,
1992 XJS V12