3 Way Switch Troubleshooting


Old 04-06-20, 08:39 AM
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3 Way Switch Troubleshooting

Hi, I have 2 3 way switches in my hallway between my bedrooms. The first has one black wire, which I assume is the common and 2 light blue wires which I assume are the travelers. The second has one yellow wire, common, and 2 light blue wires, travelers. They do the following:
  • Switch 1 up: switch 2 up is off and switch 2 down is on.
  • Switch 1 down: light off no matter switch 2 position.
  • Switch 2 up: light off no matter switch 1 position.
  • Switch 2 down: switch 1 up is on switch 2 down is off.
That is to say when switch 2 is down switch 1 controls the lights and when switch 1 us up switch 2 controls the lights.
I bought a new 3 way switch and replaced each of the existing switches with it but the behavior didn't change.
There is a switch just inside the master bedroom off this hallway that I have never been able to find a use for. It is wired as a 2 way switch and I assume completely unrelated as there doesn't seem to be any 3 way wiring in there but I thought I'd mention it.
Any ideas what the problem might be?
Old 04-06-20, 11:21 AM
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Welcome to the forums.

Typically the traveler wire colors are the same at both ends BUT that is not written in stone.

Do you have a meter ? Check the black and yellow wires to ground.
One should be live at all times. That would definitely be a common wire.
The other wire should only be live when the light is on.

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