Electricians and home handyman: help me figure out a three-way switch

The light switch for our garage is located behind the interior door when you open it. It’s awkward and inconvenient, so I want to install this wireless remote switch so it’s easier to turn on when you walk in. Obviously, I don’t want to risk zapping it by installing it incorrectly.

As it happens, the existing switch is a three-way, with its mate near the big exterior garage door. I don’t need that one, and plan to disable or remove it.

But these two switches don’t seem to be wired according to the common plan:

Here’s what mine looks like. When the switches are either both up or both down, the light is on.

            Switch 1             |                Switch 2   
               o  Red            |           Red o
 Hot Blk  o                      |                     o Blk
               o  Blk            |           Wht o

[I don’t know why the [code] tag has turned some of the characters green. Disregard it.]

BTW, I’m pretty sure my setup is not a “California three-way” [insert your own joke here], because Switch 2 has only three wires, not the four that would seem to be required.

The box for Switch 1 also has two pairs of white neutral lines, connected with wire nuts. There’s nothing in Box 2 but the three wires (R, B, W).

Can you help me figure out what’s going on here, and how to wire the controller? It has two pairs of wires, one of which needs to be connected to hot and neutral, with the other connected to the load.

FYI, elsewhere in the house I have found wiring that seemed not to follow the standard conventions for color coding, so that may be a factor here.


Have you checked that it isn’t just a case of lazy wire use with the two bottom contacts in your diagram being connected through a wire that’s black at one end, white at the other, and has a splice in the middle? That seems to me to be the only way you would get it working when both are switched up, or both down.

Yes, that’s possible, although that would also mean that the black wire at Switch 2 is actually neutral, right? How could I safely check it?

I’m not sure you really need to much. If current is flowing to your load both when Switch one is hot-blk to red and switch two is red to black, and when one is hot blk to blk and switch two is wht to blk, there has to be a connection between the two bottom wires.

I’d try disconnecting switch one and check that there are no hot wires in switch two at that point. Presumably one of the neutral wires in switch one go to the load. I’d disconnect the two neutrals from each other and check the voltages between each of them and the hot wire. The hot and the neutral that isn’t going to the load would go into one end of the controller. The other end of the controller would connect to the other netural and to either red or black. And to complete the loop you need to pick one of the wires going from switch one to switch two, connect it to the controller where switch one was, and splice it with the outgoing black where switch two was. Unless you have a way to get it to go to the load directly.

You were right, @naita, and your instructions were very helpful! Thanks very much.

I knew there were alternate ways of wiring a three-way, like the “California” method, and I was worried there might be some other method I didn’t know about and hadn’t found in Googling.

I took some bell wire and did a continuity test on the wires at each end. The red went to the red, but as we suspected, the white wire at Switch 2 was connected to the black wire at Switch 1. Very confusing!

So I looped the black load wire at Switch 2 to the red wire, and before connecting the controller, I reconnected the white neutral wires at Switch 1, then touched the black hot wire to the red wire, and sure enough, the light went on, proving that the circuit would work correctly. I hooked up the controller per your instructions, and now everything is working great!

Thanks again, @naita.


Back when I was teaching college physics labs, one of the pre-lab questions was how to wire up a pair of switches to produce the three-way effect. Most students came up with the standard way, most likely either from already being familiar with it, or by looking it up. I was very surprised when a student came up with a completely different arrangement that also worked, but after poring over it for a while, concluded that no, there really were two different ways of doing it.

And then I was very surprised again when a student eventually came up with another way, that wasn’t either of those two ways.

By the fifth one, I ceased to be surprised. So far as I know, there are five and a half different ways of doing it. At least. (The half-way is one that has the desired effect on the light bulb, but which is a short circuit when the bulb is off).

Now, there are various reasons why the standard way is the standard: It’s superior in some relevant way or another to every one of the other ways (for instance, some of the other ways have different terminals of the bulb hot in the two different on configurations, contrary to the safety convention that the outside contact should always be neutral). But the other ways work.

It would be fun to see a list of them.

It’s been a while: The only one I remember off the top of my head is like that diagram, except the two leads that are currently connected to the voltage supply, you instead connect directly to each other, and you instead hook the power supply up between the two wires between the switches (this is one of the ones with a reverse polarity for the bulb in the two on states).

Take that one, and swap the power supply and light bulb, and you get the half-solution, the one that shorts out when turned off.

I have never heard of a California-3-way. A switch with 4 wires is for a 4 way switching. That is where there are 3 or more switches.

Four wires are not required. Note that two of the wires entering each switch in the diagram are the same wire. The diagram is actually fairly misleading since the red indicates current flow, not whether the wire is hot or not. In the configuration shown, all of the wires in the upper segment are hot.

There are two junction points required to tie the traveler wire, the switch terminal, and the hot wire together, but that would typically be done with a wire nut, wago, etc.

What is key for the California 3-way is that there are three traveler wires. If there are only two, it must be a conventional configuration.

Here’s an alternate diagram for the California 3-way:

Note the two points where three black wires come together. That’s where the wire nuts would go. The switches only have three terminals each.