[PaddyMcGrath]

Folks,

I'm having the same issues with my new rear LED lights, where in only one half of the brake light LEDs are illuminating.



In this picture you can see that the tail lights (three horizontal bars) and the left bank of LEDs are illuminated with the brakes depressed.



For comparions, these are my current lights with the complete bank of LEDs illuminated along with the tail lights.



With the new rear lights, you need to utilise the original bulb socket holders, which I picked up brand new from BMW this morning. The connections on the back of the new lights plug into the bulb sockets on the holder, with the holder then connected to the car. I checked both bulb socket holders with their original bulbs, to see if the issue was with the lights or with the bulb socket holders. In the picture above, the two bottom bulbs are the brake lights but only one of them seems to be working, which is the case on both holders. In both cases, it's the outside bulb socket. I tried swapping the connections around on the back of the light to the 'good' socket on the holder and can get both banks of LEDs to light up individually so that shows that there's no issue with the lights.



Looking closer at the socket holder and I noticed that there's only five pins in the connection with the bottom one missing. Interestingly, the missing pin runs to the non-working bulb socket.



Here's the connection to the car, again with only five of the six wires with nothing running to the "sixth" pin.

If I can get the 'false' socket working, I'm sure this will sort the problem but I've no idea where to even begin so any suggestions would be hugely welcome!

[PaddyMcGrath]

Anyways, I eventually figured this out eventually so thought it might be of benefit to others ...



I took a closer look at the bulb holder and figured if I could tap the working socket into the non-working & non-connected one I might have some luck. Found a piece of wire in the garage and ...



... voilá. Both bulbs / sockets working in tandem. I didn't have any other pieces of wire for a neat solution and managed to lose that bit, but my second plan worked a treat ...



... with screwing a small steel screw in between the connections of the two sockets.



I've no idea why the bulb holder didn't work from the factory, or why the second socket was even there if there was no pin or connection for it but how and ever. Everything is working perfectly now, thought it might help someone else who might be stuck in the future by sharing!

[rockape]

i have the exact same problem Paddy may try your method, or solder a bridging wire in place.

i wish somebody could explain why the inner bulbs do not function ?

[F80M]

Good job on this fix!

[rockape]

after posting this on the uk forum, i have the answer.
the inner bulb only illuminates under heavy braking, known as BFD brake force display.