Unusual 3-way wiring for Linear WD500Z and WT00Z?

Hi, I am running into some wiring problems as I try to map out a 3-way z-wave light switch in my living room, using a Linear WD500Z Wall Dimmer Switch and a Linear WT00Z auxiliary switch. I have looked at existing posts and have found very helpful threads on 3-way dimming, but my wiring setup has me really confused. Apologies in advance if I include too much/too basic information! Just want to paint a clear picture. I attached photos of the setup for each box as it looked when wired to the old switches.

This is where I am so far:

Junction Box #1
Is a multi-gang box that houses 3 total switches on the same circuit, with a total of 6 separate lines of Romex going into/out of the box. The old switch I’m replacing is a simple on/off toggle switch. I’ve disconnected and capped four wires from the old switch: 2 black, one red, one ground. After throwing the breaker back on, my non-contact voltage meter gets a live reading on one of the black wires AND the red wire. The other black wire (which was connected to the black screw on the old switch), does not get a reading. There is a bundle of white wires capped in the back of the box, but the old switch was not wired to this bundle. Hoping this is my neutral bundle, to power the Linear.

Junction Box #2 (This is where it gets weird to me)
Is a single gang box with one toggle/dimmer switch, with only a single romex cable going into the box. Since there is only one romex in the box, there are only the usual 4 wires here: red, white, black, and ground. The white wire was connected to the Common screw terminal; the red and black wires were connected to the remaining two brass colored screws. After capping each wire, with the breaker on I get a live reading from the black, the white, AND the red wire. All of the other regular 3-way setups I’ve seen online have TWO romex going into/out a single junction box. And I don’t understand how all three of these wires are live.

1). In Box #1, how do I use my multimeter to determine which wire is the Line and Load wire for the WD500Z-1? Both the capped red and one of the black wires are live, according to my non-contact sensor.

2.) How can all three wires be live in Box #2? What can I do to troubleshoot this to determine which is my neutral and which is my true hot wire to connect the auxiliary WT00Z with the Master WD500Z?

3.) Does anything about my current wiring setup indicate that I simply won’t be able to install these Linear switches? I don’t want to burn another day if it just won’t work without additional wiring, but I don’t know enough to make that call just by looking at what wires I currently have.

Thank you for any help you can give! Happy to provide additional clarification. This community has been a tremendously helpful learning tool as I get up to speed.

Did you remove both switches and test your wires or did you remove one switch at the time? I think you were testing wires on one switch that you removed and capped leaving the other connected. That would explain why you have 2 hot wires on junction #1 and 3 hot wires on junction #2.
When testing wires in 3-way setups, you should remove both switches at the same time to correctly identify your power (line) wire. With both switches removed only one wire out of six wires that were connected should be hot.

Thanks huskyboy, that’s a good point. I did remove both switches before testing the 6 capped wires. I just tested again to make sure, and the results are the same: for the switch at Junction Box #1, the red and one of the black wires is live. At Junction Box #2, all 3 of the wires - red, white, black - are also live.

I do have a multimeter, if anyone can advise on how to use that to test some of these wires out.

I attached some photos of the actual wiring, below, in case this helps.

Photos A and B are of Junction Box #1. Photo A shows the wiring on the old switch. The black and red wires on the top of the switch are the ones that get a live reading when I have them capped. Photo B shows the wiring after I capped all the wires on the old switch. I circled the 4 wires from the old switch in Orange, and I circled the three bundles that I can see in Green. The two live wires from the old switch (orange-cicled at the top of Photo B) run directly to the same Romex; they’re not bundled. The black wire that is orange-circled in the center of Photo B is not live. It is bundled into the black bundle on the top-right.

Photo C is of Junction #2 capped wires.

Thanks again, very much appreciated!

That’s certainly is not typical setup. Sorry I’m not experienced enough to help you in this case. I think junction #2 was not part of original house wiring and was perhaps added at a later time to enable 3-way operation. However how and where was it’s spliced to I have no idea. The only thing I can make from this setup is the black wire in junction #1 that’s not getting reading seems to be the load wire.

With both switches disconnected, there should only be a single line(hot) wire. That you have four hot wires suggests that either you have a third switch in the circuit(4-way) or you are not correctly identifying the wires.

If you are unfamiliar with how to trace wires using the continuity feature of your multimeter(NEVER HOT), I would recommend that you get an electrician or someone more familiar with household electrical to help you identify the wires and how the circuit is laid out.

I just went through this exact scenario. In my main box the switch I was replacing with a WD500Z had the following:

Black = Hot
Red = Load
Red(white tag)=Traveler
Copper = Ground

The odd thing here is the white wire connected with all of the blacks. It turns out that this goes to my remote box and how Hot gets over there. because there was no Neutral in the remote box, the WT00Z would never work. I could get the WD500Z working only if the remote switch was in one particular position (or if I tied all 3 wires together). To resolve this I did the following:

In the main box I unwired the white that was with the blacks and wired it to the rest of the White bundle. I found the red load wire (by guessing).Then I Wired the WD500Z as follows:
Black to Black
Red Load to Blue
White to White
Ground to Green.
Red Traveler, snipped and capped.

At the remote box I wired the WT00Z as follows:
Black to Black
White to White
Ground to Green
Red Traveler snipped and capped.

I have attached before pictures of my boxes and a picture I found in another thread here.

I hope this helps.

@huskyboy, Thanks for the follow-up. I think you may be right about the wiring in Junction #2. It?s right on the threshold between the old house and the new addition.

@Z-waver, Thanks for the comments. There definitely isn?t a third switch in the circuit, but I do think @HansE post below sheds a lot of light on the issue.

@HansE, Huge thank you for this post. Your setup does look extremely similar to mine, and the wiring diagram is very helpful. If I understand you correctly:

–The white wire that is currently bundled with my black wires in my main Junction Box #1 is in fact the same white wire that is going to my Junction Box #2. That?s why my white wire in Junction Box #2 is getting a live reading.
–I need to turn the white wire into a neutral, so I unbundle it from the black bundle and bundle it with the rest of the whites.
–That way I?ll have a neutral in Junction #2 required for the remote WT00Z switch. Now I have to figure out the Load wire.

This makes sense to me because when I trace the white wire that is currently bundled with the blacks, it goes into the same Romex cable that houses the red and one of the black wires that went to the original switch. This Romex must be the same Romex that feeds into Junction Box #2?

I?m going to take a crack at this tomorrow and I?ll post my progress and follow-up questions. Thanks again for the post! I thought I was screwed in Junction #2 by not having a neutral for the remote switch.

Success! Here’s how I did my wiring, in case anyone else finds this thread. I did not have to use a multimeter for this. I included photos of the final wiring.

As a test, in Junction #1 I unbundled the White wire that was in the Black wire bundle (bottom left of Photo B). All three of the wires in Junction #2 went dead. So I figured that White wire must be how Junction #2 was getting it’s hot, because the other two wires in that Romex cable (the Red and the Black) previously went to the original switch, not to any power source. The key was to get a Neutral going to Junction #2, so the auxiliary switch could work. More on that under the Junction #2 description below.

In Junction Box #1, for the master WD500Z
–Connected the ground to the ground capped wire
–Connected the White wire from WD500Z with the bundled neutral White wires in the back of the box
–Connected the Black wire from WD500Z with the bundled Black wires (from the bottom left of Photo B); This bundle was my Line bundle
–By process of elimination, I found the Load wire to connect with my Blue wire on the WD500Z. Of the three remaining wires that I had unhooked from the original switch, 2 of them (the Red and the Black at the top of Photo B) went directly to Junction #2, so I knew they couldn’t be Load. The only remaining wire, the Black one in the middle of Photo B, must be load. So I connected with Blue.

In Junction #2, for the remote/auxiliary WT00Z
–The remaining wires in Junction #1 were the White, Red, and Black that were all going in the same Romex directly to Junction #2. I tied the White in with the White neutral bundle. This is how I got a Neutral to go over to Junction #2.
–I tied the Black wire into the Black line bundle in Junction #1. I relied on the wiring diagram posted by @HansE for this.
–I capped the Red wire in both Junction #1 and #2. No traveler is needed because the remote switch communicates wirelessly with the master.
–In Junction #2, I now had a White neutral, a Black line wire, and a capped Red wire.
–Simply wired the remote switch as normal, black to black, white to white, green to ground.

With power on, both Z-wave switches had the green power light on. The master switch could control the lights, on/off/dim, etc. The remote switch could not, because I haven’t associated it with the master yet. I’m about to do that, using my Vera lite.

Thanks again to the comments, and for the helpful wiring diagram from HansE!