3-Way Switch Help, No netural in one box


I a light in the garage, I haven’t bought switches yet for this light, but I am trying to figure out if it is possible. The main switch is in the garage and never gets touched and that one has a neutral. The switch in the house doesn’t have a neutral wire and that is the one that we use.

Assuming you just want an on/off it would the lzw30 or lzw30-sn would go in the garage. You can use an add on or dumb switch inside

To add on @stu1811 - If you want notifications inside the house, you’ll need to use a dimmer switch in a non-neutral configuration with an aux switch on the garage side.

@harjms OR pass line and neutral over 14/3, cap traveler, and associate two lzw30-sn. I have this is my kitchen.

*Disclaimer: This is a more advanced setup.

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So I would be able to use a dimmer on the house side and it would dim the light?

Also on the garage switch, the 3 black wires are on the same terminal, so I am assuming those are the line and the red wire is the load?

I think you’re going to have to figure out your wiring in the garage first. I know that @stu1811 and @harjms posted about how to use an Inovelli, and I’m not disagreeing with them, but I see something in your wiring that indicates you need to diagnose further.

I’d need better pictures of the garage switch, fully pulled out and so you can see into the box and the Romex coming into the box. Since in the house you have all three conductors from the same 3-wire attached to that switch, that suggests that you have both the line and the load in the garage.

What caught my attention are the conductors attached to the switch in the garage. Normally (and this can vary so there are no absolutes) this would be wired with the hot being sent to the other switch first via the black of the 3-wire going to the house switch. The Load to the light would be connected to the black of the 2-wire to the switch. The other two terminals would be connected to the red and the WHITE of the 3-wire going to the other switch.

But what I’m seeing, with a limited view in your picture, is that you have 2 black conductors connected to the garage switch. I’d expect to see a white and a red.

I’m not saying this is incorrect, but most electricians would wire this as I’ve just described. So you need to diagnose a bit to map your wiring so that you fully understand it. Better pics will help.

Here is the diagram of what I would expect to see:

Interesting grounding straps in the plastic boxes. Where are you located?

@Bry I am attached more pics, hopefully this will clear up the wiring for the garage side

So it looks like there is 2 black line wires, 1 black load wire and 1 red traveler in the garage switch. I am thinking I am going to have too open up the light fixture soon to see what wires are in there.

I am located in Toronto, Canada

Thanks, but it’s still tough to see in your box. I (or you) need to see where those conductors are going.

I see a single black on the common screw. I’m guessing that is the load. Temporarily remove it from the switch and test USING A METER between it and the white neutral bundle. See if there is voltage testing with the other switch in both positions. I’m thinking there won’t be.

It seems like you’re saying the other two hooked to one of the brass traveler terminals in the constantly hot line. Hooking 2 to the same terminal makes sense when you want to send the hot downstream, but why attached to traveler terminal???

Where is the white from the 3-wire connected? Actually, see where all three are connected with that box.

Maybe there are different conventions in Canada (I’m in the US), but I just can’t get my head around how this is mapped.

And before I get too far along, do both of these switches work properly? In other words, can you turn the light on and off using either switch, with the light in both conditions. Don’t be offended, but it wouldn’t be the first time someone figured out while they were doing this that something was wrong. Also wondering because that black on the black terminal is wrapped in the wrong direction, making me wonder if an electrician wired it.

@stu1811 You posted with a solution before. Do you understand what’s going on here?

I thought line was coming in the box over white (from fixture) then hopping over to the other box via white on 3 wire Romex. It lands on COM the travels back via Blk/Red to the first box as travelers. Then BLK connected to COM goes back up to light fixture.

Edit: hopefully not a switched neutral.

Maybe, but the OP said the 2 blacks were hot, so I asked him to test. But if you’re correct, why are there TWO blacks on a traveler terminal in the garage? If you were sending a hot downstream that makes sense but not on the traveler terminal.

If you are correct, there should be a white to black on the 3-wire in the garage box. Can’t see from the pix. OP will have to test and show all the connections in the garage box.

So there are 3 romex coming into the garage box, two of them must be for the plugs in the garage, there black wires are connected to the common terminal. The romex that is connected to the light fixture both the red and black are connected to the switch. I was able to open the light fixture and attached picture of it. It looks like the neutral in the garage box is connected to the black in the house box.

I am getting a multimeter, but won’t have it till tomorrow.

The switches work properly, the house was built in 2016 and I am the only owner and haven’t touched these switches before. The electrical would have been done by a licensed electrician.

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I’ll give this a look over in the AM. @Bry may already have it solved by that time though.

I was hoping to see a 2 wire at the light but looks like 2 3 wires.

Nope, waiting for the metering.

Also, when you post pics, please pull everything out as far as it will go, including the wire-nutted bundles. Makes it easier to diagnose. Also, for the switches, it’s helpful to see the backs because in some cases the backstabs were used and we can’t tell what terminal the conductors are attached to.

The 14/2 wires in the top right and bottom left of the garage box are power, in and out. Really doesn’t matter at all which is which here. The 14/3 in the top right goes to the garage light. The black and red are travelers.

The wire on the right of the garage light comes from the garage box. The wire on the left of the garage box goes to the house switch. The travelers switch to being the red and white wires. The return from the house switch is the black wire.

The house switch just has the single 14/3 from the light box.

BUT, I see another switch in the house box WITH power and very possibly a neutral. Is that true?

With the current wiring, you can’t put a switch into the house box in a 3-way configuration with neutral to the switch.

So, what do you want to do? You have these choices,

  • Possibly re-power the garage light wiring and feed the garage lights from the power going to the other switch or dimmer in the house.

  • Put the switch in the house in a non-neutral configuration with an aux switch in the garage.

  • Put the switch in the garage in a neutral configuration with an aux switch in the house to control dimming.

  • Put 2 smart switches in a neutral configuration and associate them.

  • Blank the garage box and put the switch into the house only in a neutral configuration.

Yep. Just want to confirm the terminal connections. It’s a bit tough to tell with the backstab connections being used. I’m thinking that this is going to be a light-in-the-middle neutral in the garage (for this leg) configuration.

I misdiagnosed the setup. Looks like you guys have made progress since I looked

I am still waiting for the multimeter since we are in lockdown and no stores are open. Looking online at the 3 way switch diagrams, it definitely looks like the fixture is in the middle of the 3 way. I took another picture of the switch, so 2 & 3 are connected to the common terminal. 1 is connected to the traveler terminal. Just wanting clarification on which black you want me to test with the neutral?

@PJF I would like to be able to dim the light from the house box. I am hoping that I might be able to use 2 smart switches so I can see what the level for the dimmer is.

There is another switch in the house box that has a neutral, but that one is on a different breaker and I am pretty sure that isn’t safe to use that neutral.

Ok, way better pictures so this makes sense now. You should confirm, but 2 and 3 are connected to the common terminal. As @PJF mentioned, this is like the line in and out of your box, so I would expect one of those conductors to be constantly hot (when not connected together).

So it appears you have a light in the middle, like this:

Typically, you’d put the Inovelli in the garage given this wiring, but that’s not what you’re looking for.

I don’t think you mentioned if you need a switch or if you can use a dimmer. That will vary your choices a bit because the dimmer is a bit more capable than the switch. But if you load is fluorescent for example, you’ll need to stick with a switch.

One solution is to use an Aux switch in the house, but there are others. Depends on the switch/dimmer question to some extent.

You are correct in that you cannot use a neutral from a different circuit.

This is what I would do.

Disconnect all the wires in the garage box. Pull the 3 wires from the 14/3 up and out at the top left of the box so they are out of the way. Connect the black and white wires on the 14/2 conductors in the garage box together and tuck them tight into the back of the box keeping them away from where the 14/3 cable enters.

Now, use the power and neutral from the other circuit in the house.

  • Connect the power and neutral to your new smart dimmer.
  • Connect the neutral to the 14/3 white wire.
  • Connect the load terminal of the smart dimmer to the 14/3 black wire.
  • Connect the traveler terminal of the smart dimmer to the 14/3 red wire.

In the light box, connect the white and red wires together. Also, connect the light between the white wires and the black wire from the left 14/3. Cap the black wire on the right 14/3 wire.

In the garage switch box, cap the black wire and connect a dumb switch or aux switch to the white and red wires.

Yes, when I opened up the light fixture, it looks like the light in the middle connection. I already have 1 spare Red series dimmer, so I don’t mind getting a second one and being able to dim the light from both places.