[jeantarrou]

I noticed a dim taillight a couple months back, been troubleshooting it when I find free time, which is pretty sparse these days!

Anyway, LCI e91, it's the inside tailgate running/brake light. After some research I saw a bunch of threads describing a grounding problem in the wiring that was causing a short in the circuit and dimming the taillight. I didn't have any evidence off a short but I did the DIY anyway, no remedy. So I inspected further and found a small circuit board with two wires attached to it that is located in the lens housing behind the bulb socket, it has some light corrosion on it, looks like some water intrusion damage? I tried cleaning the board as best I could, no remedy.

This circuit board with the wires seems to be simply completing the taillight circuit because if the bulbs are plugged into the socket and the socket is plugged into the harness they won't illuminate at all unless the socket is installed in the taillight and making contact with the taillight housing circuit board wires.

So my questions are...

Can I cut that small circuit board out of the equation and just connect the two wires without it, thereby completing the circuit?

I can't purchase just this circuit board, I have to purchase the whole taillight, does anyone have the amazingly obscure knowledge regarding the compatibility of just this small circuit board across the different e90 (or others) models? ie. could I buy a smashed inner taillight from an e90 and scavenge the board from it?

Thanks in advance.

[matteblue3er]

That circuit board is most likely doing some type of regulation for driving the LEDs. Removing it may result in the LEDs drawing unregulated current until they burn themselves out.

[jeantarrou]

Well the bulb in question here on my e91 isn't a LED, but I have pretty much been assuming the circuit board is performing something similar to what you described. It must perform some sort of task, why else would it be there?

[jeantarrou]

Bump