4 way switch in 1947 constructon--help needed

So I’m trying to figure out how to do a smart switch in a house that was built in 1947 by a mechanical engineer that was pretty smart from what I hear and see. Anyway, 3 switches control 1 set of lights and this is how each box tests:

#1 Box, 4 wires:
2 always hot
2 only hot when on

#2 Box, 3 wires:
2 always hot
1 only hot when on

#3 Box, 3 wires:
1 always hot
2 only hot when on

and the wire colors don’t make sense. I know there are places in the house red wires are always hot. Box #2 has a red wire that is also connected to another 3 way switch next to it via a jumper and it is always hot. The red wire at box #3 looks to be a true traveler because it’s the one that’s not hot when the lights are off. Red wire connected to the black screw on both of those boxes.

Thanks in advance for the help!


Others can comment on the wiring, but by far the easiest solution, assuming you’re in the United States, for this kind of retrofit is just to get one Lutron Caseta master switch and three of their battery operated Picos. :sunglasses: You also need one Lutron Caseta SmartBridge to enable integration with SmartThings. (One SmartBridge can support up to 40 Lutron devices. Most of the switch models do not require a neutral wire.

The solution is easy, inexpensive because the pico’s are inexpensive, well engineered, and works very well. I use this brand in my own home.



Pico batteries last about 10 years.

The main question with an older home is whether you are OK aesthetically with the switch style. If you are, then you don’t have to worry about the wiring.

So hopefully others will go into the wiring issues with you, but I did just want to mention the Caseta option as well.

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I want to figure out a way to use a regular GE 12727. Mainly because I own 1 with an add on switch. I have the same switch installed in my workshop so sticking with what I know I guess.

Understood. You should talk to the people in the GE wiring FAQ thread, they should be able to help you.

Also, you probably already know this, but in the US most wire colors are not mandated by code so people can and do use Red, black, and white, for pretty much anything, sometimes just depending on what the last coil of wire left in the toolbox is at the end of the day. So the colors don’t necessarily mean anything.

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Yeah, I’ve noticed the colors being like they are. I ran a red wire from the box the other day so I could have 2 drops with the same line separating them half way down the run.

Antone else with ideas of how the hook up that GE smart switch?

Here’s drawing if it helps:

You need a neutral connection which you do not have in order to use the GE switches. Being the wiring is so old it looks like they just tapped into power from some switches in order to power lights in different rooms. Not sure if you have a ground either but that would also be needed.
Basically in the box with the master switch you would need Line (hot), Load (light), Neutral, Traveler (Usually red), and ground. The addon switches would each need a neutral and traveler line.

Personally I would just go with lutron in your case or you will need an electrician to run new lines to get a neutral.

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I have no problem rewiring it myself. The house is wired with Neutral wires. I have this switch in my workshop. I just put the cover back on the breaker box from where I ran that Line I talked about or I’d take a picture of it. I’m wondering if it is wired with power to the light and the Neutral never makes it to the switch. This guy was very smart (creative), remember…

The half of the basement closes to you never has ceiling the half further away does but you can see I’ve removed a bunch following lines trying to figure this out. I have from the last switch (#1 actually) to go but I’m blocked by something I can’t move. Don’t remember but that’s when I decided to ask the forum here.

Thank you so far…

Seems like you have standard wiring for what is called a 4 way switch (which is really two 3 way switches and one 4 way switch). You can look up the wiring for this but your #1 box is switching the “traveler” wires of which there are two running between box 2 and box 3. Every 3 way switch has one line or one load wire and two traveler wires and that is what is in your box 2 and box 3. Box 1 is the two traveler wires “cut” and passed through on a special 4 way switch which just switches the current from one traveler to the other.

You would need one of the 12727 master siwtches and two of the GE “addon” switches. You can wire box 2 or box 3 with the master and the remaining two with the addon switches. You would use one of the traveler wires to pass through the “hot” wire through each box and the other traveler wire would be the wire used for the addon switches. You’ll need a basic continuity tester to find which of the traveler wires is the same in all 3 boxes - remember to disconnect all the switch wires in box 2 and box 3 before testing for continuity since you can’t do that on a live circuit. After you figure out which are the travelers the remaining single wires in box 2 and box3 are the line and the load wires (you can tell the difference by turning the circuit back on and seeing which one has line voltage).

As mentioned above you will need a neutral in all 3 boxes (don’t jumper to the ground wire or box).

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I only have 1 add on switch at the moment. I think box #3 is obvious from the color and how it tests. Can I add the main smart switch here for now and leave the other alone for now? Until I get 1 more add on switch…

This is Box 3, the white and red are only hot when on, black always hot. Asexpected…

switch on the right, sorry…

Pay attention to the dark screw terminals of the two 3 ways switches. That’s your key to find out your load and line. The dark terminal screw of the 3 ways switch with always power regardless of light on or off is your line. The dark screw with power only when light on is your load. Ignore your 4 ways switch because that’s just your travelers.
Don’t mix smart switch with dumb switch. You will damage your smart switch.

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So rkrasny,
I’m going to put the master on Box #3. That seems t be the easy one.

The other 2 boxes both have 2 that seem to be always hot. I’m using a Klein non-contact line tester btw. I have a meter if you think I need it.

The first thing you’ll do is examine the two three way switches you are going to remove. That black, red and yellow wire will be connected to screw terminals on the switch - two of these will be the same color (like brass) and one will be another color (like black). If that’s the case then the two wires on the same color screw are classically the “travelers” I was talking about for a 3 way circuit. The third wire will be the line on one 3 way switch and the load on the other 3 way switch. If you review the basics of how a 3 way switch works you’ll understand this better but all the switch is doing is transferring the line voltage to one or the other traveler wires through to the other switch which either places it in continuity with the load or not depending onthe other 3 way switch position.

You’ll then remove both 3 way switches and when you do that you will line voltage on only ONE of the wires in one of those 3 way boxes. All the other wires will NOT have line voltage.

You will then use one of the two travelers to pass the load from the 3 way switch box into the other box (because the master GE switch needs line and load and traveler in the same box as well as neutral you said you’d supply).

You will then install the master GE switch into that box and once you do that and turn the power back on the light will actually work from that one switch.

Next you’ll install the two “addon” switches. All those require is line voltage, neutral and connection to the “traveler” coming from the master switch. The same traveler can be used for both addon switches.

The only issue you may run into is that 4 way switch box. If it only has those 4 wires in it then you’ll need to run line voltage and neutral to it from anywhere else.

As always it is best to perform all your wiring with the breaker off for that circuit (after you’ve investigate where the line and load wires are). I also always wire those ge switches with the air gap pulled out (that’s not how they come out of the box). This protects the switch if you happen to connect it to voltage before being fully hooked up. Those switches can be internally damaged if that occurs.

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Here’s a better picture of Box #1. Still pretty obvious that it’s two sets of, 1 Black 1 White, for 4 wires total. They are still taped together (I’m going to add a zip tie;-).

1 pair goes to the top two Brass Screws
2nd pair goes to the bottom two Black Screws

…if that tells you anything. I was assuming it was 2 line and 2 neutral, before asking…

No, that’s your 4 way switch. That’s just the two travelers that are going from one 3 way switch to the other 3 way switch. The travelers are themselves being switched (that’s how a 4 way circuit works - in fact you could add a 4th, 5th or infinite number of additional switches by just switching the travelers but I’ve never seen more than a 4 way circuit which has 3 switches controlling one set of lights.

The proper way to handle this box is to set it up to contain an addon switch, I described the procedure in my prior post.

Looks like you have cloth insulated wiring which is still fine in most jurisdictions as long as the insulation is in reasonable shape.

They used white (or maybe yellow wires that have faded) for one set of travelers and wrapped a piece of electrical tape on it. That’s the universal designation for “I used a white wire but it’s NOT a neutral, it’s line voltage”. Personally that insulation doens’t look great, you should at a minimum consider wrapping it fully with electrical tape to help protect it.

Also, take all this with a grain of salt, I’m not an electrician, just a very experienced handy person who is quite familiar with all this stuff (end disclaimer)

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I tried to follow where they go but there’s one place I simply can not see where it makes it past the I Beam. It looks like 1 set goes to box #2 and the other set goes to a line and natural connection but it sounds like I need to remove that 1 piece of wood so I can see exactly where they both go.

Can’t do it tonight with people trying to go to sleep, it’ll take a hammer stuff…

I figured it out and you’re right. 1 pair goes to each of the other boxes. The Red at box #3 (1 of the 2 hot only when on) comes out from there to the beginning of the run of lights it controls. That would mean the black is the power and there is no Neutral. Can I tie into any Neutral and what gauge wire do I need to use? I have some 18/2, solid copper. Could I use both together or is that sketchy?

Come to think of it I have some 14/3 romex I could replace the entire run and pick up neutral there.

Needs to be the same gauge as the hot and load wires. If you use 14/3 make sure it’s a 15A breaker and not a 20A (which would require 12G)

You should probably get a bit more comfortable with your tester - you need to test for continuity and line voltage. You can’t always rely on wire color because not everyone adheres to conventions and even if they do you need to know what those conventions are (like the elec tape over your white traveler wires).

You can pickup neutral from anywhere, ideally the same circuit as the lights but it doesn’t have to be because it is just the switch load on it. You should make sure you don’t have a fancy breaker called an AFCI on that circuit because if you did then you’d have to pickup the neutral from the same circuit. From the look of the condition of your cloth insulated wires I don’t think this will be a concern.

You keep talking about the one or other hot for the travelers - please note that that really isn’t the line (hot) or the load - those are exclusively at the other 3 way switch boxes. The travelers are simply switching the line voltage. I would strongly encourage you to google 3 way and 4 way switch diagrams and I think it will all make much more sense to you. And make sure you feel comfortable with everything - this is electricity and when done really improperly it becomes a fire hazard. I don’t mean to scare you but you should have a good intellectual grasp of what you’re trying to accomplish as well as a little grounding (pun intended) on reasonable electrical techniques.

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I’m not relying on colors at all. As I was saying, I’m removing the ceiling so I can physically look at the wires. I may not have been perfectly clear when I was describing that stuff. I want to see it al the way to the breaker. I am opening all junction boxes so I know for sure what is going on. and I have testers…

All the wire is the same gauge and it is a 15 amp breaker. I know Some stuff.

I don’t have half the lights on in this picture and it’s trashed from projects but it’s a recent project replacing the original bar from 1947. It had a sink made out of bent metal and a drain pipe that ran right down the middle of the shelves from upstairs. The rehab project started when I decided to replace a receptacle box. The project kinda brew up and I’m not finished. I added a few LED Black Lights a couple days ago. …That’s bubbling water!