For close to a year, I chased a right rear brake light issue on my car. Some days it worked, other days it didnt.
After replacing the bulb, swapping bulbs, cleaning all ground connections, soldering a loose wire going to a ground pin, I almost gave up...
Recently, I found the culprit! I removed the rear light housing from the car. After removing the bulbs, I then separated the bulb housing plate from the main base, carefully using a small screw driver to pry up on the unit. This plate is simply held in place with a few molded tabs that sit around the main housing.
On the inside of the bulb plate there are flat metal strips that connect each of the bulb sockets to the center where the wire connects into the unit. It basically looks like a simple circuit board.
The problem with my rear brake light not working was caused by a hairline crack in this metal strip going to the brake light socket. To fix, I put a small amount of solder over the crack.
Fixed!
My comment here is to just stay with it, and dont give up. You will find the problem. Trace each connection, check all grounds, make sure they clean, connected and making contact. These cars are built well, and being old need a bit of TLC.
Bob
bpossel (Memphis, TN.)
'71 280SL / '97 E320
