Only half of my drivers side REAR brake light is lighting up

[Stevae]

Hey guys,
I have a 2009 335i E92, and many years ago I upgraded the taillights to LCI LED's. They came with the resister boxes to aid the conversion without needing to code. These lights have worked flawlessly for many years now. Suddenly, my drivers side brake light only lights up halfway. I hadn't changed anything, so wasn't sure what the deal was. Curiously, I wrote the company I purchased the brake lights from, and they sent me an entirely new brake light unit to my surprise. I install it, and the same thing was happening with the new one, but the other side works perfectly well. So, it's DEFINITELY something to do with the brake wires on that side, and not the light itself, the FRM module or a fuse. I am perplexed as to what has happened, and how to fix it, other than investigating the wiring which is a time involved task. Any help from those who know would be much appreciated. Thanks in advance.

[Greydog]

High Stev

Welcome to the Forum

No one can diagnose a problem without investigating it, It could be anything from water ingress to a faulty unit 

I am afraid the only way is check and test all connections 

Dave