Hey whats up guys I own A 1987 760 gle with 80k and my brake lights and third dont work. Ive checked the bulbs,connections,brake switch on the pedal and the brake failure relay I have run out of ideas on what it could be any help would be greatly appreciated

 

My guess would be a bad ground wire somewhere, likely the trunk.

Those cars have a paper/plastic thing that the wire in the light assembly runs through. You could put something in the car to make the brake peddel depress like a cinder block or broom stick, then go in the trunk and play with the bulb sockets.