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enter image description hereI have a single switch in my garage for the light outside my garage. I have a single switch at my front door for my porch. I want to have it so either switch will turn on both the garage, and porch light.

I ran 14/3 wire from 1 switch to the other. I have 2 3 way switches. Thought that's what I needed, but not sure if it's a 4-way.

https://imgur.com/gnoO40m

  • Can you also run a 14/2 cable? – Harper - Reinstate Monica Dec 28 '19 at 17:47
  • I could, but don't have one. Was hoping I could use everything I already have – Doug21 Dec 28 '19 at 17:57
  • I do have extra 14/3 I could run, and take the red out to make it 14/2 – Doug21 Dec 28 '19 at 18:18
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    Smart boy Doug. You took pictures before taking everything apart. – JACK Dec 28 '19 at 19:07
  • Which switch box is that a photo of the inside of, and can you post a photo of the inside of the other switch box as well please? – ThreePhaseEel Dec 28 '19 at 21:10
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This needs to be done in a 2-step process.

Rewire it so one of the switches powers both lights.

For this, we need to run a /2 cable between the switches. (or alternately, from the controlling switch direct to the light). If you use /3 cable, leave the full length intact on the useless wire, but cap it off. Could come in handy later.

Inside the non-controlling (temporarily defunct) switch box, take the cable (hot and neutral) that goes to the light (i.e. the switched hot on the old switch) -- and mark its black wire blue, and its white wire gray. On the new /2 cable, also mark both ends that same way. Note that we are marking the white wire gray.

In the non-controlling box, connect these two gray wires to each other, and these two blue wires to each other. They will effectively "pass through" this box without connecting to any switches. That will be permanently that way.

Back in the controlling box, you need to pigtail or legally double-tap the switch. Assuming there is one single bundle of white wires, the gray wire joins it. The blue wire goes to the switched side of the switch. (if it's on 24x7 you got the wrong side).

OK, so now you have both lights working from one of the switches.

Upgrade this to a 3-way circuit

Now, lay a /3 cable between the two switch boxes.

Then follow my instructions on the other post! Remember we will not touch the blue/gray splice in the far box.

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  • Thanks for the reply. That seems like a lot of work. I just finished the project. I bought a 3 gang box for the front door, and used a 3 way in the garage, and 3 way at the front door. So I have 3 light switches at my front door. One for the porch light, one or inside the front door, and one for the garage light. I do appreciate all the help, but It was a lot of work running the 14/3 wire let a lone adding another. – Doug21 Dec 30 '19 at 16:37
  • @Doug21 oh, that,s a much simpler solution. I was under the impression that you needed to switch the porch light from the garage! In the future I strongly recommend you figure out how the wiring needs to be done before installing cable (or in fact, wven buying it). – Harper - Reinstate Monica Dec 30 '19 at 18:19

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