As the title suggests, this doesn't happen all the time. For the past few evenings, I've noticed that every once in awhile when I hit the brakes, my brake lights will come on, go back out, then come on again a second or two later.

I've never known a brake light switch to act this way but since it's both sides and not just one or the other, I'm leaning that way.

 

Mine had this issue it was the fuse looseing connection ?

 

Oh yeah, I always forget about the simple causes. I'll check that today.

 

Your xj automatic ?

 

Yes.........AW-4

 

Checked the fuse...........good, even looks new-ish.
Checked all the wiring I could find...........all good too.
Bought a brake light switch from work and it is the strangest looking contraption I've ever seen.
MotorAllData is almost completely useless on vehicles this old and the only service manual I could find is a Haynes and it isn't much better.
Every single other brake light switch I've replaced, screwed into a hole and had a check nut to keep the proper adjustment so, this one has me a little baffled as to how to go about replacing it. Has anyone had to do one of these?

 

self explanatory when you look under dash goes on brake pedal/booster rod actually easier than most not way up under dash