Red On/Off with Add-on. No Neutrals. Line + 2 travelers in 1 box, load + 2 travelers in the other

I’m trying to replace an existing 3-way with a red series on/off switch and add-on switch, but none of the wiring diagrams match my situation.

Box 1 has a three-wire cable with a hot line wire and two travelers.

Box 2 also has a three-wire cable. Two of the wires continuity test as being tied to the two travelers from box 1 (although the colors have changed). I assume that the third wire is the load.

There is a junction box in the middle. I opened it and it was scary. I don’t want to dig into it if I don’t have to.

First question. Do you have two wiring issues or one? In another threadl, which was split to a new thread, you said that what you had matched a diagram I drew. That diagram doesn’t match what you described here, so trying to understand how many issues you have.

I created this thread. An admin tried to be helpful and created the other thread.

None of the “official” wiring diagrams from Inovelli match my situation. I think my wiring matches this diagram that you posted.

I verified that the line is in box 1. I connected the two travelers together and did a continuity test at box 2 to find the travelers and (what I assume) is the load. The travelers pass through a intermediate junction box, so the traveler colors change, but they pass the continuity test.


Got it. Glad you posted this again as I had posted this configuration and a non-standard one. This one is a standard power to the light in the middle so there is a solution.

There are a couple options depending on which box you want the switch in. Take a look at this thread starting at my post. Also scroll down. How you do it depends upon which box has the non-neutral hot and which box you want the Inovelli in. You will need to use an Aux in the other.

This should get you started, but post back with questions.

One question that I have is does this require a red series dimmer?

I’ve got red on/off switches and black dimmers, but no red dimmers in my tub of switches.

Both of the wiring diagrams are non-neutral configurations. So they require a dimmer. It doesn’t have to be a red dimmer, a black dimmer will work in a non-neutral configuration as well.

Red and Black switches require a neutral, so neither of those will work.

Can I use a black dimmer with the add-on switch or use two black dimmers?

You can use an Aux with a Black dimmer.

You can’t use two dimmers if you’re following the 2nd diagram, as there is no way to power the 2nd dimmer in a non-neutral without a load. If you can get a the light box where the two 3-wires meet, you ought to be able to re-wire it to send a hot and neutral to each box, but without re-wiring at the light, I don’t see any way to do two dimmers.

I’ve got it partially working. I have the add-on switch in box 1. The line and one traveler are connected up to the neutral. The other traveler wire is connected up to the add-on traveler.

The traveler from the add-on is connected to the traveler connection on a Black dimmer in box 2. The old traveler wire (tied to line) is connected to the line and the load is connected to the load.

I thought that I got it configured for non-neutral with an add-on switch, but I must have missed something.

The dimmer works as expected, but the add-on is ignored.

That sounds correct wiring wise. You tested the black conductor in each box (while disconnected) to determine which one was the line, right?

The switch has to be configured for a three-way momentary. Which hub are you using?

Setting the dimmer to three-way momentary was the necessary magic. I tried setting the aux from the switch and it apparently didn’t save. I then tried setting it to 3-way Toggle in Hubitat. Neither worked.

Once I set it to 3-way momentary, the add-on switch started working properly.

Thank you for your help.


Mark as resolved please!