I made a terrible mistake. I removed a 3-way switch from a 4 way switch setup without labeling the existing wires. Now the light the switch was attached to doesn't come on. I was going to put a blank in place of the switch but now I just want to put the switch back the way it was. I had just capped the three wires separately. I'm very sure the black and red wires were connected directly to the switch. The white wire probably was somehow twisted with all the other white wires from the other switches.

There is a 4 gang box upstairs with switches in it controlling four different lights. All lights are on the same circuit. All white wires except one are twisted together in this box. One white wire from a 2-wire (leftmost) is not connected to anything and has tape covering the end. I assume power comes in and is hooked into every light there. The switch I tried to remove from this box is a 3-way switch connected with a 3 wire. Downstairs is another 3-way switch connected with a 3 wire. (I assume they are connected together.) Red wire is top left, black is top right and white bottom right. Also downstairs is 4-way switch with two 2-wires coming in, blacks on left whites on right. The light controlled by all three switches is closest to this 4-way switch. There is one 2-wire coming into the light, I presume from the switch close to it. Directly above this 4-way switch is the 4 gang box upstairs.

Is it correct that all I have to to is add another white wire to the removed 3-way switch and twist it and the white wire from the capped white from the 3 wire together with all the other white wires and hook up the same way as the 3-way switch in the basement?

4-gang box with 3-way switch removed

  • Can you post a photo of the inside of the box where the removed 3way switch was? Dec 3, 2017 at 19:49
  • @ThreePhaseEel I've added a photo but I'm not sure how helpful it will be. As you can see it's a big mess in there.
    – fullerm
    Dec 3, 2017 at 20:17
  • Can you positively identify the three wires which had gone to the 3-way? Dec 3, 2017 at 23:46
  • @Harper those three dangling orange capped wires went to the 3-way. The white one must have went to the mass of other white wires with another one coming into the 3-way. It wouldn't work otherwise right?
    – fullerm
    Dec 3, 2017 at 23:57
  • 1
    They don't make 14/3 Romex in yellow-yellow-black or yellow-yellow-red. You end up using Romex in the colors it's made in, and that means colors mean nothing in 3-way circuits. Generally neutral never goes to a switch, so if a white goes to a switch, it's not a neutral. Dec 4, 2017 at 0:06

1 Answer 1

  1. Power off.
  2. Pick any 2 of the capped wires formerly attached to the 3-way.
  3. Nut those two together.
  4. Leave the third wire nutted independently.
  5. Power on.
  6. Throw any other switch in the 3/4 way group. Does the light turn on or off?
    • all other 3/4-ways work correctly -- fail*. Pick a different pair and go to 1.
    • lights do not work in either position -- success. The two nutted together are the messengers.

Mark both messengers with yellow tape (or other appropriate marking) -- messengers are interchangeable, so you don't need to distinguish them from each other.

The two messengers go on the brass screws of the 3-way switch.

The remaining wire is common and goes on the black screw.

* Or, if you just want to eliminate that 3-way, you can stop right here and you are done.

  • It may be worth noting that swapping the messenger wires will have the effect of swapping which combinations of up/down switches turn the light on and which ones turn them off. It may be desirable to arrange things so that if all switches are down, all lights will be off. If that isn't the case, swapping the messenger wires will change that.
    – supercat
    Sep 23, 2022 at 21:20
  • @supercat true, but so will physically rotating one switch 180 degrees. Sep 23, 2022 at 22:52
  • Fair point. Various factors may cause either approach to be easier.
    – supercat
    Sep 23, 2022 at 23:00

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