Replacing 2 three way switches that control a group of recessed lighting with Smart Insteon switches. As background, Insteon switches require a neutral and don't use travellers since there 3 ways connect wirelessly.

Normally the hot(s) get connected to the Insteon black, and the red (load) get's attached to the light in one box and capped in the other box. And both get attached to ground and neutral. With this set of neutrals it seems a bit different since one of the switches already seems to have a white wire attached and the other switch has a screw that is attached to two wires. Tried attaching based on what made the most sense but neither switched powered on.

Can someone help suggest which current wires match up with the news switches, since what worked for the rest of the house doesn't work for these.


High resolution version as requested

3 way Switch under recessed lighting 3 way switch across room

  • Wanted to add another note. Unplugged the hot red from both switches and turned on the circuit breaker. The light turns on and I'm still able to control the lights via the switches, however then if i flip one switch to turn off the light, the other switch can't turn it back on, and vice versa.Both of those unplugged red wires are still hot even when unplugged. Also when all the wires are plugged in, if i unplug the black cold wire from the switch in the top right of the above image the light doesnt turn on.Does any of that help? Aug 1, 2016 at 19:52
  • Is there another junction box involved in this circuit? Also, can you get us MUCH larger photos of the junction boxes? Aug 1, 2016 at 22:25
  • Also, it really helps to know how the wires are grouped as they exit the junction box. And what's happening with every wire in any of the groups that go to these switches. For instance the left switch must have a minimum of 3 wire groups - the power supply, the cable to the lights, and the cable to the other switch. Of course the power supply will be shared with other switches, we're not worried about that. Aug 1, 2016 at 22:34
  • @ThreePhaseEel Yes this is a three way switch (so two gang boxes), which are shown above via a picture and a diagram. The diagraph below the pictures show the actual wire hookup. Let me know if there is something else you need to know about the junction box not pictured in the diagram and happy to provide! Aug 1, 2016 at 22:40
  • @Harper Yes, if you look at the diagram above I note how the wires are bundled. That is for instance the left diagram, there is a note saying that the red and black next to each other are coming from one bundle, and the other red and black come from one bundle. And the diagram on the right has a note mentioning that the red black and black come from the same bundle. Was that what you were looking for? Aug 1, 2016 at 22:45

1 Answer 1


This particular situation will involve rewiring the old dead end 3-way.

The white tied to the blacks needs to be rewired as a neutral. Currently it is wired as a common (hot). Then one of the travellers needs to be rewired as a permanent hot. This will allow your dead end Insteon to be powered up.

The black and red that where tied together is the switch leg. It ties to the red on the Insteon. The rest should fall into place.

Don't forget to turn off the breaker(s).

  • Thanks for your reply. So in the top left plug, the previous red/black that were together goes to red on insteon, great. Ground goes to ground. Confused on where to plug in the remaining red and black. In the other box there is a hot white that you mention that needs to be rewired but not sure what you mean by rewiring it. If you could let me know which should attach where like with the red/black, that would be great! Aug 2, 2016 at 22:56
  • I created a graphic and labelled each wire 1A, 1B, etc, that was it may make it easier to say which should go to which. Such as 1B should go to 3C and 3D. Not sure about the others. Didn't include grounds in graphic but of course would connect those too. i.stack.imgur.com/hIMVX.jpg Aug 2, 2016 at 23:14
  • @cchiera The remaining red black are the travelers. As mentioned earlier, you will need to send permanent power on one of the travelers to the dead-end Insteon, AND a neutral. The white tied to the blacks needs to be removed and tied to the other whites so it can be used as a neutral at the dead end Insteon.
    – Kris
    Aug 2, 2016 at 23:19
  • I'm not really interested in the schematic.
    – Kris
    Aug 2, 2016 at 23:21
  • In the 3 gang box the white tied to blacks are for a different switch in that same gang box, so didn't want to touch any of the wires going to unrelated switches in the same multi gang box. But if your saying that should be done and won't negatively affect those other switches I can try that. Which would involve removing the white tied to the 2 blacks for that other switch, and attaching that white to the other bundle of whites that are used by the new insteon. The schematic was more so would be easier to describe/name exactly which wires should hook up to accomplish what you are suggesting. Aug 2, 2016 at 23:52

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