Two Ground Wire?

[Prost]

I got this picture from eBay, I want to connect my homelink mirror and use this light to get power, I know the red/green wire is +12V power, but there are two brown ground, which one should I use?

[Gregs///M]

Either is fine. Ground in BMW's, all of them, is always solid brown.

[oldmann]

Two grounds, either will do. 2nd would be for next piece needing a ground.

[treff-7]

Either is fine. Ground in BMW's, all of them, is always solid brown.

Two grounds, either will do. 2nd would be for next piece needing a ground.

It does matter which one you use! One of them is a constant ground, the other one is only grounded when you open a door. Check which way you need to slide the switch for the light to be constantly on and the wire on that side is the constant ground.

Edit: Also i believe only one of them is solid brown (the constant ground). The other one is brown-purple or something like that.

[StereoInstaller1]

It does matter which one you use! One of them is a constant ground, the other one is only grounded when you open a door. Check which way you need to slide the switch for the light to be constantly on and the wire on that side is the constant ground.

Edit: Also i believe only one of them is solid brown (the constant ground). The other one is brown-purple or something like that.

This.

[Prost]

It does matter which one you use! One of them is a constant ground, the other one is only grounded when you open a door. Check which way you need to slide the switch for the light to be constantly on and the wire on that side is the constant ground.

Edit: Also i believe only one of them is solid brown (the constant ground). The other one is brown-purple or something like that.

Which one you connect to your homelink as ground? the constant one or the door only one?

[Gregs///M]

It does matter which one you use! One of them is a constant ground, the other one is only grounded when you open a door. Check which way you need to slide the switch for the light to be constantly on and the wire on that side is the constant ground.

Edit: Also i believe only one of them is solid brown (the constant ground). The other one is brown-purple or something like that.

Good find, my mistake. The picture looked like they were common with each other but "dome light trigger"...of course.

[treff-7]

Which one you connect to your homelink as ground? the constant one or the door only one?

The constant one. Otherwise it will only work when you have one of the doors open. The switched +12V from the check panel will determine whether it's on or not. That way it will be energized when you turn the key to ACC (the first click).

Good find, my mistake. The picture looked like they were common with each other but "dome light trigger"...of course.

This is a typical sign of knowing too much. ;)
The next step will be when you agree and disagree with yourself at the same time for personal reasons...

[Prost]

The constant one. Otherwise it will only work when you have one of the doors open. The switched +12V from the check panel will determine whether it's on or not. That way it will be energized when you turn the key to ACC (the first click).

Got it ;)