Clearance light

[Mboys]

2016 ALPINE. Smashed my left side rear running light. Bought after mkt replacement with one wire and surface mount ground. Took off smashed light. There are 2 black wires comming out of the 5er??. Do I simply test one to find the hot wire and cap off the other??? Neither are LED if that helps.

[bobbecky]

Whichever wire is the ground will need to be attached to the metal part of the light fixture and then the hot wire goes to the terminal of the bulb socket. Unfortunately, electricity must have an in and out path to make things work. That replacement fixture was probably designed to be screwed to a metal part of a vehicle, which would be the grounded side of the fixture, so the one wire to the socket would have been all that was necessary, but with a fiberglass exterior wall, the other wire is needed.

[Mboys]

The after mkt light will actually be attached to metal on 5er. Thinking about attaching ground wire (whichever one that is) to attachment screw on light as opposed to capping it off. Just seems odd the wires were not color coded in the first place. Thank you for your reply.

[CedarCreekWoody]

Originally Posted by Mboys

The after mkt light will actually be attached to metal on 5er. Thinking about attaching ground wire (whichever one that is) to attachment screw on light as opposed to capping it off. Just seems odd the wires were not color coded in the first place. Thank you for your reply.

Yes, attach it, not cap it. Most likely either wire can be ground.

[flybouy]

Originally Posted by Mboys

The after mkt light will actually be attached to metal on 5er. Thinking about attaching ground wire (whichever one that is) to attachment screw on light as opposed to capping it off. Just seems odd the wires were not color coded in the first place. Thank you for your reply.

Did you pull the wires out of the hole and find where the wires from the light is attached to the wires from the camper? Find that connection and disconnect it. Then with a voltmeter find out which wire is positive and which is negative. Install a ring terminal on the negative wire and place the screw thru the terminal, thru the ground ring on the light fixture then into the side of the camper. Connect the 2 wires remaining and secure with the second screw.

[Mboys]

Thanks so much. Sounds like a plan. My non electrical brain has a hard time with either wire could be used as ground. I suppose it's just completing a circuit right?

[flybouy]

Originally Posted by Mboys

Thanks so much. Sounds like a plan. My non electrical brain has a hard time with either wire could be used as ground. I suppose it's just completing a circuit right?

Well it depends, if the trailer body is metal then it absolutly makes a difference and using the positive wire as the ground will short the circuit either blowing the fuse or melting the wires. Doing it on a fiberglass (non conducting) material may not cause a problem but why not do it properly?

[Mboys]

Thanks for clarifying. Makes sense. I know what I need to do now thanks to everyone.