Extra wire in light fixture

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Tuatara
Posts: 3
Joined: Sun Feb 15, 2015 10:58 am

Extra wire in light fixture

Post by Tuatara » Sun Feb 15, 2015 11:03 am

I have seen a half dozen videos on youtube about changing a ceiling light fixture and they are all basic with only black and white wires. We are attempting to change ours but we have an extra red wire coming down from the ceiling and an extra green wire on another ceiling fixture. What should I do with these wires?

Tuatara
Posts: 3
Joined: Sun Feb 15, 2015 10:58 am

Re: Extra wire in light fixture

Post by Tuatara » Sun Feb 15, 2015 11:37 am

I will try and give a better explanation.

On 2 attached ceiling fixtures there are 2 white wires, 2 black wires, 1 red wire and a ground. I have no idea what the red wire is for. My wife took apart the old fixtures and she didn't pay attention to what the wires were hooked up to. The new fixtures have the basic one white and one black wire.

The 3rd fixture is really confusing. Attached to the ceiling is 2 black wires and 4 white wires but the new fixture has one black, one white and one green wire.

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Aaron
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Joined: Sat Jan 03, 2015 4:03 pm
Location: St. Paul, MN

Re: Extra wire in light fixture

Post by Aaron » Sun Feb 15, 2015 1:51 pm

If you have a black, white, and red, then it's almost most certain you have two circuits in that box (the red and the black, the white is neutral). Any light fixture only uses a white and a black. I'm guessing the red wire might have been to turn the fan on and off--perhaps there was a ceiling fan there once upon a time.

The good news is you can experiment until it works.

Be sure to kill power to the circuit at your main breaker panel or fuse box.

Put a wire nut on the red, and just push it back in the box. Connect the white and black of the new fixture to the corresponding wires in the box. Install a light bulb, turn the power back on, and see if the light goes on and off with the switch.

If not, then kill the power at the your main breaker panel or fuse box, and connect the black of the fixture to the red of the box. Put a wire nut on the black wire of the box. Turn the power back on, and see if the light goes on and off with the switch.

One of them should be the switched leg.

Don't forget to ground your light fixture once you've figured out its wiring. There's often a thin braided wire that comes out from the fixture. This needs to be connected to a green or silver screw on the strap that goes across the round box.

Tuatara
Posts: 3
Joined: Sun Feb 15, 2015 10:58 am

Re: Extra wire in light fixture

Post by Tuatara » Sun Feb 15, 2015 3:11 pm

Thanks, will try it later. Going to a meeting right now.

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