Up front, I do not know what I am doing.
I would like to replace two three-way switches with one smart single-pole switch, in a home without neutral wires. I believe my wiring configuration is best represented (with the exception of the neutral wires, which I do not have) by this diagram
based on the fact that one switch is in obvious proximity to the main panel and the other is on the opposite side of the room in question, with the fixture in between them. I would specifically like to eliminate the switch between the fixture and the main panel, and use the smart switch on the other side of the fixture.
From what I've gathered from Google results, what's needed is essentially
- Remove the panel-side switch, and join the line wire and one of the traveler wires with a wire nut; and
- At the other switch location, attach the black wire (connected to the black screw) to the "line" lead of the smart switch and the "same" traveler wire to the "load" lead on the smart switch.
What isn't clear about those two steps is how to determine which traveler wire at the other switch location corresponds to the one joined to the line wire at the panel-side switch, without trusting the wire colors to be meaningful. I would think I could determine that by turning on the light (from either switch) and noting which of the two traveler wires at each switch had voltage.
- Is my presumption about what my wiring configuration is reasonable?
- Is what I want to achieve possible given that presumed wiring configuration?
- Should I be worried about whether doing this is safe?
- Am I right about how to determine which wires to join together, and which wires to connect to the smart switch?
- Given 4, do I even need to actually know 1, or would this plan work regardless of the wiring configuration?