Another LZW31-SN 3 way non neutral question

Wife tolerance factor is waning, help me Inovelli community you are my only hope…

Old house built in the fifties, trying to install LZW31-SN in the kitchen. Not an electrician but here is the switch I would put the LZW31-SN in

The two white wires are throwing me off.

Here is the other switch

May the force be with you all.

Invest in a multimeter and/or indicator pen. The 2nd switch controls same lights as first picture?

For testing switches to find which wire has power I prefer one like this


  • Multimeters are good but often needs 3 hands.
  • The non contact “pens” are OK if the wires are well away from other wires, if not they can give false readings.

What to look for:

A 3-Way switch looks like this internally:
image The black screw in the diagram is called the common. Your switches are very old and I can’t be sure the positions of the screw in my diagram matches the diagram. You will have to look for some indication on the switch.

Looking at the bottom switch: The “red” wire looks like the common and leaving the Black and white as “travelers” so it likely looks like this:


I think the most likely location for the dimmer is in the upper photo.
The goal is to find the source of the power and hopefully find a neutral.

Although the dimmer can operate without a neutral, without a neutral the dimmer steals power through the load. If the load is too small, you may need a bypass to get the extra power needed by the dimmer. With a neutral this is not a problem. So if a neutral can be found it would be the better installation.


Better pictures will help. We want to see both the connections to the switches AND the wires in the box. So pull the switches out and take pictures so we can see what’s in the box . . the other wires . . what’s wire-nutted together, etc. Also, remove the tape from the switches for the pictures. While tape is a good practice, we want to see the colors of the screws to which the wires are connected.