I have a 1988 jag XJ6. The passenger side stop, indicator, and tail lights were all out. I discovered it was a blown capacitor in the circuit board of the bulb failure module as well as a blown fuse. I replaced the module as well as the fuse. Now the tail light works all of the time but the indicator and stop lights only work intermittently. I have looked for any visible split wires and checked all of the connections. Any ideas what else it might be?

 

Switch sides with the BFM's and see if the problem "follows " the BFM from the passenger side. you probably have more bad inside the BFM than just a Capacitor.
amyway this process will nail down a bad BFM.
GOOD LUCK

 

I have replaced the entire BFM with one that I know works (tried it on the drivers side) and the lights still continue to do the same thing.

 

I am grasping at straws here, but I just had this intermittent bulb happening to me too: I was trying to fix a rear turn lamp. I shined up the contacts in the socket and made sure the bulb was clean. What it turned out that I had was a broken but not burned off filament in the bulb. You're sure your bulbs are good? Good luck. Keep us posted.

 

Hey, sorry it has been so long since my last reply. I ended up just wiggling some wires around and tying some others up. The lights now work all the time so for now my problem is solved. Thank you to everyone who gave a reply!