3-way switch puzzle

[zepper]

Hey guys,

I can't be the first person who's done this, so I'm sorry if I'm asking something that's been asked (many times?) before.

My wife wanted to replace our existing dining room ceiling light—a three-bulb mini-spot, off to the side—with a pendant light directly over the dining table.

So I cut a hole in the ceiling in the right spot, added a cross-brace between two ceiling joists, installed a new junction box there, and ran its cable over the joists to the existing box. I connected the new cable's hot, neutral and ground leads where the old fixture's were connected.

Two switches, at either side of the room, control this line. I could see the red "travelers" in the original box, but I didn't think I needed to fuss with them, as the existing light wasn't connected to them. (You may be catching on that I don't know much about 3-way circuits.)

The switches worked with the old light. Now, only switch #1 turns the new light on and off—and only if switch #2 is off. If #2 is on, there's no light, and #1 has no effect.

In the existing box, there's also a mysterious black lead connected to a white lead... Was I supposed to do something with that?

Here's a photo—what did I do wrong? (I'm married, fortunately, so being wrong is a regular thing.) Thanks for your help!

 

[Sparky617]

This video does a decent job explaining it. There are three possible ways to wire a three way circuit and the video covers all three. If you have questions after watching post up in this thread.

https://www.google.com/search?q=thr...me&ie=UTF-8#kpvalbx=_ROjYXtLAHbGKggf65I3QCg45

 

[JoeD]

Please confirm you make NO changes to the switches. You connected your new cable to the same two black and white that was connected to the old fixture. If that is true then it should be working.

 

[user 4883]

AS JoeD says, if it was just a swap, then it should work. Maybe there is a loose connection somewhere. I'd start by checking all the wire nuts (old connection and new connections).

 

[zepper]

This video does a decent job explaining it. There are three possible ways to wire a three way circuit and the video covers all three...

Three ways to do a three-way? That's funny (and could seem nasty, if we were people who thought that way).

Do you think rewiring it in one of the other ways could solve a problem like this? Why would it matter?

Please confirm you make NO changes to the switches. You connected your new cable to the same two black and white that was connected to the old fixture...

AS JoeD says, if it was just a swap, then it should work. Maybe there is a loose connection somewhere. I'd start by checking all the wire nuts (old connection and new connections).

Nope, I made no changes to switches. All I did was add a few feet to the existing hot/neutral/ground leads where the previous fixture was connected.

I've taken your suggestion. I checked and reconnected everything. (I took a bit more insulation off a couple leads so they'd twist together more completely.) No effect.

We could simply not use the 2nd switch, but I hate leaving stuff in a baffling state, y'know?

 

[Sparky617]

zepper said: "Three ways to do a three-way? That's funny (and could seem nasty, if we were people who thought that way).

Do you think rewiring it in one of the other ways could solve a problem like this? Why would it matter?"

Rewiring is not required, the three ways of wiring it depend on where you the power enters. I posted the video so you could analyze your circuit to figure it out. Rather than trying to explain it in a message here. Do you have a voltage meter? Or even a simple tester to determine which of your black wires is hot? The first thing to do is determine where the power is coming into the circuit. Then it becomes a matter of figuring out which wires go where.

 

[JoeD]

Nope, I made no changes to switches. All I did was add a few feet to the existing hot/neutral/ground leads where the previous fixture was connected.

Then one of your switches has gone bad. I would try a new switch at #2 first.

 

[zepper]

You guys are so kind and helpful—I appreciate it! Unfortunately, no amount of helpfulness compensates for fundamental thickness on my part.

I now realize what the "problem" is. The other switch is in an out-of-the-way place, over by our laundry room door. We don't enter or leave the house that way at night, so we don't usually operate the light from there.

When we moved in a few years ago and I upgraded the lighting to LED (the previous owners still had incandescents), I replaced this light's main switch with an LED-compatible dimmer. Somehow I failed to notice it was a 3-way circuit, and didn't reconnect the red "traveler". (It's a complex box with 4 switches, see... Okay, I've no real defence.) At least I remembered to turn off the breaker, so I could be here to write this to you today.

Only now did I notice the 3-way wasn't working, because I was replacing the fixture (not just the bulbs) and thinking about wiring.

Obviously my brain needed a bit more wiring too.