I have this new (to me) house which for the most part seems to have updated wiring.  This was great for the few rooms I've put my Insteon switches into up until I got to one room which has a ridiculous number of multi-way switches.

This is my first....

So the kitchen light is a three way.

One box (let's call it the right one) only has red, white, black, and ground.  No neutral or any other leads.

The other box (let's call it the left) has three sets of Romex coming into it.  Only one of those contains three leads.

I need to put a KPL into the right box and a regular Insteon switch into the left box (see my sloppy diagram).

What things do i need to test for, or what do I need to determine in order to get a neutral off to the right box without adding any wires?

 

 

Three ways via Insteon are really simpler than a traditional three way - have one Insteon switch actually control the load.  Then just power up the other Insteon switch and link it to the other switch.  If you want to you can also create a scene and use that instead of the linking process on the switch itself.  

If you want to use the KPL just power it up - I'm guessing the red wire was the traveler so you won't use that - and assuming you have a real hot and neutral where you have the KPL shown you can create the scene, put both switches in it and control the load on the paddle switch.  

3 minutes ago, atmarosi said:

Three ways via Insteon are really simpler than a traditional three way - have one Insteon switch actually control the load.  Then just power up the other Insteon switch and link it to the other switch.  If you want to you can also create a scene and use that instead of the linking process on the switch itself.  

If you want to use the KPL just power it up - I'm guessing the red wire was the traveler so you won't use that - and assuming you have a real hot and neutral where you have the KPL shown you can create the scene, put both switches in it and control the load on the paddle switch.  

Yes, I’ve set up a dozen virtual multi ways in the past.  That’s not the question.

The question is how to determine which wires are which?

I usually throw breaker.  Then un do all the wire nuts and separate the romex lines.  Then turn power back on and see where the real hot is. Either a non-contact stick or multi meter is your friend to find the input of the hot.  
 

then you can wire it back up more that you know which is bring in the power. Continuity tester on the multi meter can help identify where the lines are going. 

It looks like the 2 blacks tied together in your left box are the hots which will need to power both switches. You show all of the whites tied together which can not be the case at this time but does need to happen to send the neutral to the right switch and both switches need the white neutral to work. Then the single black wire going up in the left switch I would assume is your switch leg which will tie to the red wire on the left switch. The red wire that goes between the boxes can be capped off on both sides as well as the red wire from the KPL in the right box. To add this is my best guess from your diagram and all wires need to be verified with a meter.

To add to @tazman's guess, if this is an overhead light, then it is very likely that the 14-2 romex coming into the top of the left box is your load, and the 14-2 romex coming into the bottom of the left box is your line. But always better to check with a voltage tester.

As he said, in the left-box, conenct all the whites together and connect the black from the 14-2 romex in the bottom, the black from the 14-3 romex in the bottom, and the black (line) from the switch together. Connect the red wire (load) from the switch to the black from the 14-2 romex coming from the top. 

In the right box you have black (line) and white (neutral) from the keypad to black and white, respectively, from the 14-3 romex. The red (traveler) for the 14-3 romex is capped in both boxes.

Again, always best to test and know what your line (hot) is, but if you end up guessing wrong which 14-2 romex in the left box is the line and which is the load, it could fry your switch, but I would think the more likely result would be that neither the switch nor the keypad would operate (no LEDs illuminated or long beep), and you could turn off the breaker and swap them out. 

Edited September 6, 20232 yr by Goose66

14 hours ago, tazman said:

It looks like the 2 blacks tied together in your left box are the hots which will need to power both switches. You show all of the whites tied together which can not be the case at this time but does need to happen to send the neutral to the right switch and both switches need the white neutral to work. Then the single black wire going up in the left switch I would assume is your switch leg which will tie to the red wire on the left switch. The red wire that goes between the boxes can be capped off on both sides as well as the red wire from the KPL in the right box. To add this is my best guess from your diagram and all wires need to be verified with a meter.

Not all of the whites are tied together.  That might be just my terrible drawing skills.  The white from the 14/3 (left box, lower right set) goes to the switch.

14 hours ago, Goose66 said:

To add to @tazman's guess, if this is an overhead light, then it is very likely that the 14-2 romex coming into the top of the left box is your load, and the 14-2 romex coming into the bottom of the left box is your line. But always better to check with a voltage tester.

As he said, in the left-box, conenct all the whites together and connect the black from the 14-2 romex in the bottom, the black from the 14-3 romex in the bottom, and the black (line) from the switch together. Connect the red wire (load) from the switch to the black from the 14-2 romex coming from the top. 

In the right box you have black (line) and white (neutral) from the switch to black and white, respectively, from the 14-3 romex. The red (traveler) for the 14-3 romex is capped in both boxes.

Again, always best to test and know what your line (hot) is, but if you end up guessing wrong which 14-2 romex in the left box is the line and which is the load, it could fry your switch, but I would think the more likely result would be that neither the switch nor the keypad would operate (no LEDs illuminated or long beep), and you could turn off the breaker and swap them out. 

I started down this route, but ran into not knowing how to get a neutral line over on the right side.

1 hour ago, MWoods329 said:

I started down this route, but ran into not knowing how to get a neutral line over on the right side.

As was stated above you wire the white from the three wire going to the right box in with the rest of the white wires (neutrals) in the left box.

On 9/5/2023 at 1:53 PM, atmarosi said:

I usually throw breaker.  Then un do all the wire nuts and separate the romex lines.  Then turn power back on and see where the real hot is. Either a non-contact stick or multi meter is your friend to find the input of the hot.  
 

then you can wire it back up more that you know which is bring in the power. Continuity tester on the multi meter can help identify where the lines are going. 

That's what I needed to hear.  Thanks!