Electrical Wiring in the Home/3-way switch wiring puzzle



Most of the light switches in my 1958 tri-level, were original to the house, and they were push-button type. A couple have failed in the ten years that we've owned this place, and I've replaced them with traditional toggle switches.

Now, merely for cosmetic reasons, I've replaced a couple 3-way switches, but I've screwed up some how, and can't make the light work from both locations. I reinstalled the original push-button switches, thinking that I put the wires back in their original locations, but obviously, I didn't. Same problem. I've shotgunned and switched the wires in several ways, but without success. I could go through all of the 32 possible wiring combinations, but the smart thing to do is to ask an expert.  

The downstairs box has two white, a black, and a ground. The upstairs box has two black, a white, and a ground. None are marked. Can solve this puzzle as if you only saw the wires hanging out of the box?  I do have a volt meter and can identify which ones are hot, but other than that, I'm stumped. Any help would be appreciated. Thank you very much!

The color coding means nothing with three way switches. There are also a lot of combinations of the positions of the switches in relation to the power source and the wire going to the light.

The main thing is to look at the switch. One screw is one color, and the two other screws are another.  These two that are the same are the travelers, and they connect to the same two on the other switch.  Normally those wires would be in the same cable, and the wire going to the other switch could be in another. (depending on the positions). These wires could be white, red or black.

The single screw color on one switch will connect to the hot power coming in, the single screw on the other switch will connect to the hot wire going to the light. These wires are usually black.

Hopefully you did not disconnect the wires connected to each other. If you did, it would be really hard to figure out where everything goes to.
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Electrical Wiring in the Home

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Bob Sponaugle


Just about any home wiring question. (not appliance repair) I have done all kinds of home wiring for myself, including adding a new breaker box, etc. Please, questions from North America only. Please be specific with details.

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