I would like to know the correct way to wire a new (replacement) light fixture.?

Question

I removed an old light fixture which is connected to only 1 switch. The cable into the fixture's electrical box had 4 wires (black, white, red, and a bare copper wire). The old light fixture had 3 wires (black, white and green). The old light was wired like this: Black (box) to black (old fixture), white (box) to white (old fixture), red (box) to green (old fixture).

My new light fixture has only 2 wires, and a bare ground (black, white and ground). I assumed the green wire in the old light fixture was the ground. So I first wired the new light fixture's ground into the red wire (as well as black to black, and white to white). When I turned the circuit on, the light was on, even though the switch for the light was off. When I turned the switch on, it blew the fuse.

Next I left the red wire unconnected, white to white, black to black, connected the ground to the box. Result: light on even though switch was off, switch did not turn light on or off.

Thanks for your help.

Yes I am sure that there is (currently) no other switch controlling this light fixture. I was thinking that this switch may have at one time been a part of a 3 way, as the research I have been doing suggested that red wire = 3 way switch.

Tech Dude and Brent C. Thanks, your answers have been helpful. I think that the ceiling fan is a definite explanation for this. When I get home tonight I will check the way the switch is wired. I am thinking that maybe the Red wire is the hot wire from the switch (mistakenly), and the black (or the white) is the constant hot wire for the fan? Does that make sense to anyone?

Answer 1

Yes the red is the switched wire and that should go to the black of the fixture and you should cap off the black wire and make sure you ground the light to the bare copper wire. Green wire are always grounds and should never be put to anything but a bare or green wire and for next time buy a cheap voltage tester (about 5 bucks) and test the wires ( one lead to a colored wire and one to the ground or white wire) and have some one hit the switch

Answer 2

The color code used in the US is black for the hot conductor, white for the neutral conductor, and green or a bare copper wire for the ground. Red is used when there is a second hot conductor.

For an electrical box in the ceiling, sometimes two switched hot conductors (black and red) are run when the house is built. This is so that sometime in the future the homeowner could install a combination ceiling fan and light without a lot of difficulty. One wire would control the fan and the other wire would control the light. But for just a light fixture, the red wire is left disconnected at both ends.

If your original light fixture had its green wire connected to the red wire in the box, this was wrong. It should have been connected to the bare copper wire. The fixture would still have worked because the ground wire is only for safety purposes to prevent electrical shock.

Your new light fixture should be connected black to black, white to white, and bare wire to bare wire. But you say that the light remains on even when the switch is turned off. However, this is how the original fixture was wired (ignoring ground which is irrelevant). All I can suggest is that you examine the light switch to see how it is wired. There is something as yet unexplained.

Answer 3

What you have is a fixture wired to acept a ceiling fan, the extra wire is a constant supply incase you want to control only the light at the switch and continue running the fan. With your new fixture, just go black-black, white-white, the bare wire is your ground, tape off the extra.

Answer 4

I smell fish. A green wire is an equipment grounding coductor. It should never be connected to anything other than another green wire, a bare copper wire, or the steel box itself.

Open up the switch box and tell us what is in there, and how the switch is wired.

Answer 5

sounds like you have a three way switch and didnt even know it. are you sure there isnt another switch some where that controls that light?????????