Hot Topics: What to Do with Red Wire

gloved hand working with wires in ceiling light fixture

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Original Post: What to Do With RED Wire?

Yupster - Visiting Guest

I am putting up a new light fixture. The fixture has a ground, a black and a white wire. The junction box has these also, BUT, there is a RED wire also. Hence, my question, what do I do with the RED wire?

Yupster #2 - Visiting Guest

The answer is that the Red Wire is the Hot Wire from the switch itself. You are wiring your fixture into a junction box where buku wires come together. Hook the white to white, ground to ground and RED to the BLACK Light Fixture Wires. The other conglomeration of black wires does not connect directly to your fixture.

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John Nelson - Member

Yupster #2 may be right, but we need a bit more information to be sure.

Are there any other wires in the ceiling box other than the ones you mentioned? Make sure you look carefully. There is exactly one black, one red, one white, and one ground?

The most likely explanation is that this ceiling box was prewired for a ceiling fan. Is this possible? Any chance you have an extra switch on the wall that you've always wonder what it was there for?

My advice would be to hook black to black, white to white, ground to ground, and put a wire nut on to cap off the red. If this works as expected, then you're done. Otherwise, cap off the ceiling's black wire and hook the fixture's black wire to the red wire instead (as Yupster#2 says). If this now works, you're finally finished.

If the above solutions have any problems, then answer all my questions above and we'll go from there.

P.S. If you're not both yupsters, I suggest you change your password.

Wgoodrich - Visiting Guest

I suspect John is probably right and possible the first post may possibly be right.

I suggest that you open the switch box and see if a red wire is either connected to a spare switch as John suspects or even wire nutted off inside the switch box intended for future use as a fan switch leg if a fan is installed in the future. Then you should be able to confirm John to be right and where that red wire nut is coming from.

Let us know how you come out.

Good Luck

Yupster - Guest

To clear up any confusion, I responded to my own question!

I tried both of the approaches that you guys mentioned. First, I capped the red wire and went black to black. The light fixture came on immediately and flipping the wall light switch had no impact on anything.

Then, I reversed this procedure, capping the blacks off and connecting red to the black fixture wire. This solved the problem as the wall switch now properly operates the light fixture. I want to thank both of you for helping out.

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