3 way switch problem.

Blade_316

I have a 3-way switch setup that doesn't quite work... Switch 1 works as a master, if it is off the light won't work at all. If switch 1 is on switch 2 works fine. I couldn't figure how to wire to get a 3-way action.

I bought the house this way and at first I thought it was just a bad switch so i replaced them both and the problem remained. I opened both boxes and the light itself and here is what I found.

Any thoughts?

[Updated Image]

Jim Port

The white in D needs to go to the Common.

Does cable A go to the fixture?

Stubbie

I agree with Jim just interchange white and black at switch 2.

Power is at the light fixture coming in on the two wire cable. The three wire cable at the light is cable A which goes to switch 1. C and D are the same cable. cable B is onward power to somewhere else.

Cable A is also carrying the neutral for cable B.

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Stubbie

Blade_316

You are right the power starts off at the light. But switching the black and white on switch 2 jumps the breaker.

Here's the redesign. What do I try next?

joed

White on switch 2 needs to be on the common for the new drawing to work. Swap the white a nd black wires at switch 2.

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oberkc

Switching black and white on switch 2 looks correct to me, as well, assuming that wire colors have the standard meaning. If this trips your circuit breaker, then there may be things about the wiring that are misunderstood. I would start checking for voltages at key places to confirm that the wiring is proper and as you expect. This may require the disassembly of the switches from the wires.

Also, the white wire of cable C is now re-used from a neutral to a line conductor in this application. This would be a violation of electric code without remarking. I suggest wrapping some black electric tape around both ends to indicate that this is now an energized wire.

joed

An explanation of what I see.
Power is coming in at the fixture and feed to switch box 1. At switch box 1 power is continuing on to feed another part of the circuit via cable B at the bottom of the drawing. Red is feeding switched power back to the fixture.

White brings power to switch 2 and should be on the common at switch 2. Red and black are the travelers.

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Blade_316

I just tried switching back white & black on switch 2 and it trips the breaker.

I even tried out various other combinations on switch 2 without any luck.

Blade_316

To be able to draw the diagram correctly, I did disassemble everything. I then worked my way from the power source. Everything seemed fine. As far as I can tell...

joed

Then your drawing is not acurate. Go back and try to figure out which cable go where again. Where does cable B go? Was it added later? It might not be able to be used as intended.

The black and white at sw2 appears to be the same balck and white we see at the fixture. So the three wire cable from the fixture appears to go to switch2.

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Jim Port

In the original post it looked like there was a deadend 3 way. The OP also said the power came in to SW1.

Sounds like some more questions need to be answered.

oberkc

Have you tried probing for voltages and grounds/neutrals? Do you get the expected voltages when the switches are pressed. I am having a lot of trouble seeing how the black/white wire exchange would cause a short, given the way it is drawn. I would expect that one could connect all three together with a wire nut and not cause a short. This is why I continue to suspect there is something else going on with the wiring.

With all the wiring removed bare, I assume you saw voltage at the 2-conductor wire at the fixture, and nowhere else. Correct? Did you check to see that none of the other wires had a short to ground anywhere, or short between any two?

HIVOLT

It's been a long day so bear with me. As I look at the drawing there seems to be a problem with both switches.

In switch 1 take the black wire off the side of the switch with the single screw and swap it with the red wire that is not on the common screw. In Sw 2 swap the white and black wire. To me it looks like the travellers are swapped and the common wire on Sw 2 is the switch leg.

Blade_316

Doing this also trips the breaker. (depending on switch positions of course)

This is the correct diagram. (I've updated the one in the first post to this, to avoid confusion)

Blade_316

Sorry about the confusion, power goes to the fixture.