Bad earth left side brake light

[Kevinthegerbil]

Hello all. I have a 2006 X3 3.0M (E83) and an annoying bad earth on the left (passenger) side brake light. Trouble is that I can't find anything that tells me where the earthing point is for this light. Can anyone point me in the right direction please? Thanks in advance.

[X5Sport]

Follow the brown wires.  Always the 'ground' on a car and should lead you back to the ground point.

[Horizon]

[quote="Kevinthegerbil"]
Hello all. I have a 2006 X3 3.0M (E83) and an annoying bad earth on the left (passenger) side brake light. Trouble is that I can't find anything that tells me where the earthing point is for this light. Can anyone point me in the right direction please? Thanks in advance.
[/quote]
Has it got the LED strip lights or conventional bulbs. Mine has the LED rear sidelights, as has my E93. I had the rear sidelight warnings on my E93 and when I checked all the lights were on, this continued until it would sometimes work randomly.
It's a common problem on the 3 series. I ended up having to replace the full light unit as the LED strips are built in.
6 months later the inner light started doing the same, so fitted another replacement complete light fitting. Both were around £90 each from ECP

[Kevinthegerbil]

Sorry, should have clarified that mine has the regular filament bulbs.

[Kevinthegerbil]

Thanks for the help guys. As I don't want to start ripping out trim panels to hunt for the earthing point, would it be feasible to splice into the brown cable and basically establish a new earthing point closer to the rear light cluster?

[Horizon]

[quote="Kevinthegerbil"]
Thanks for the help guys. As I don't want to start ripping out trim panels to hunt for the earthing point, would it be feasible to splice into the brown cable and basically establish a new earthing point closer to the rear light cluster?
[/quote]
The battery is in the boot under the easily accessed lift up floor, that is where the main earthing point is.
Edit. Also check the light unit, as the E53 suffers from corrosion on the bulb fittings, which causes random bulb out warnings.

[X5Sport]

[quote="Kevinthegerbil"]
Thanks for the help guys. As I don't want to start ripping out trim panels to hunt for the earthing point, would it be feasible to splice into the brown cable and basically establish a new earthing point closer to the rear light cluster?
[/quote]

Yes.  Anywhere metal for the body shell will do, or tap across to another earth, or as above go straight to the battery.

[Kevinthegerbil]

That's great, thanks all!