Today, I wanted to replace a dimmer with a normal switch for my dining room lights. When I pulled the dimmer out of the wall, all 3 wires just fell right off of their connections. I'm surprised the house didn't burn down years ago…
Anyways, whoever installed this did a terrible job and I'm now left with 9 wires sticking out of the wall.
- 3 white wires bound together
- 3 ground/copper wires bound together and connected to the dimmer's green wire
with a metal "staple" - 3 black wires in which I do not know where they
go.
I removed the wire nut off of the white wires so I was able to see which direction they are going. 2 white wires coming from the left, 1 white wire to the right, same with the black wires.
Now, I've been trying to read up on which wires go where, but I'm stumped at this point. I know I will have to wire nut all of the white wires together, and of course run the green to the switch ground.
Where do the wires go? Do I need to use a 3 way switch even though I only have a single switch to control a single light at this point?
Thanks!
Best Answer
The simplest thing to do is to turn the breaker on and figure out which black wire is supplying the current. (This is arguably one of the more dangerous approaches, but it is safe if you follow precautions like have someone guarding the wires so they are not touched while the power is on.) Use a multimeter and test the voltage between the ground wire and every other wire. Exactly one black wire should have 120 volts on it.
If not, stop and report back here.
Once you identify which black wire is hot, turn the breaker off.
Then wire nut all of the whites together. Wire the "hot" black wire you identified to one other black wire. Turn the breaker on. Note if the ceiling light came on. If not, turn the breaker off, hook up the other black wire to the hot black wire and turn the breaker on. Note if the ceiling light came on. Turn off the breaker.
Now you know: 1. which black wire is the "hot" wire, and 2. which black wire goes to the ceiling fixture, and 3. your "other" black wire, which probably provides power to another switch or outlet.
You should wirenut the "hot" wire and the "other" wire together with a short scrap of black wire to create a pigtail. Connect the pigtail to the switch. Connect the black fixture wire to the other side of the switch. And your whites should already be wire nutted together from before. So just hook up the ground wire to the switch, and you're done!