we recently moved to a condo and I was looking to replace some dated dimmers with regular on/off light switches to be able to use LED bulbs. Ended up taking off the two light switches but did not write down or take a picture of how it was previously wired.

I've seared the forum and found some guidance for people with similar issue, but mine seems to be a little different. I have 4 black wires coming out, 4 white wires that are pigtailed together, and 4 ground wires pigtailed together. The ground wires have two wires coming out that connect to the light switches.

As I understand it from other posts, its not uncommon to have the 4 white wires pigtailed together.

My issue now is I have no idea to which terminal to connect the four wires. I've tried all the possibilities and best I can get is to get one of the light switches to work. Also, apparently one of these wires continue to the bathroom and I can't get any of those lights to work now.

Lastly, I did try to pigtail the two black wires on the left side and pigtail the two black wires on the right side, and then run a wire to each switch. That made both switches work (and the lights in the bathroom) but each switch powered both lights (i.e., if I turn one switch on, both lights go on. Then if I turn the second switch on, nothing changes. And the lights cannot be individually controlled).

If helpful, I can take a picture of the wires as they are now but essentially it mirrors the sketch below (ignoring the ground wires).

enter image description here

Actual image of box: enter image description here

enter image description here

  • Is it a three way switch/(previously a dimmer) setup? If so, the blacks are probably: 1) Power in 2) power out to the next switch and 3) the other two blacks might be travelers to 3 way switch connected to the same fixtures. Not quite up to code, they should have been code taped (colored tape to identify the travelers), but frequently ignored. It's SO IMPORTANT to take pics before you start taking things apart. Let us know if this is part of a 3 way switch (2 switches controlling a fixture or set of fixtures) then we can better help. Commented Feb 4, 2022 at 19:39
  • You have two "in" wires and two "out" wires. You'll have to try and figure out which are which and which belong to which light. Photos may help us offer clues. If you can find the hot wires you're halfway there.
    – isherwood
    Commented Feb 4, 2022 at 19:41
  • No three way switches, just two regular one-way switches. Completely agree that I should have taken a picture... I always do now (or at least draw down a diagram). Let me take some picture and add them here.
    – gonvart
    Commented Feb 4, 2022 at 19:53
  • Original post updated w/ pictures of the electrical box.
    – gonvart
    Commented Feb 4, 2022 at 20:02
  • How many circuit breakers do you have to throw to get ALL the power off in this box? Is it one, but a double-wide or with handle ties? Are the lights in working order as far as you know? Commented Feb 4, 2022 at 20:45

1 Answer 1


Apply logic; And some means of keeping track of each black wire individually.

One is power in, one is power on to bathroom, one is one set of lights, one is the other set of lights.

If you have connected things together and the bathroom lights work (without the switches affecting them) then one of the connected wires is the power, and the wire it's connected to is the bathroom light. Since you muddled things up by connecting two sets of two, disconnect one set of two, and if it does not affect the bathroom lights, then that was the two lights that are supposed to be switched.

If it DOES affect the bathroom lights, then that was the incoming power and the power to the bathroom lights. The other pair must be the lights.

If the light switches are affecting the bathroom lights, you didn't say that.

The incoming power connects to the bathroom light feed, and one side of both switches.

The switched power to each light connects, individually, to the other side of each switch.

  • Thanks... Actually got there just before I saw your note. Found the live wire using a multimeter and then trialed and errored which wire was what. Everything now turns on with the switch and lights in the bathroom work.
    – gonvart
    Commented Feb 4, 2022 at 22:55

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.