3 way switch problems

Old 08-18-04, 06:38 PM
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3 way switch problems

I have a setup with a staircase, switch at the bottom, where the power comes in, and a 3 way wire going upstairs to a switch with a 2 wire going to a light. I have tested by checking the wires and know which wire is which going upstairs, and have one as the common, it is connected to the common on both switches. The whites are tied up, all connected. The other black going from down to up is on the side with the common wire. On the other side of the switch is the other 3 wire wire. Now it worked fine with old switches, and in this setup as well. when you trun ont eh bottom switch, it goes on, but it needs to be on for the top switch to work, and if the top switch is off, the bottom one will not operate. Sounds like a common wire problem, right? I am lost, I have tried different combos, but after testing and identifing which wire is which, I do not know what to do. Any ideas?? Thanks.
Old 08-18-04, 06:44 PM
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There should not be a wire that runs between the common screws on the two switches. Is that what you said you had?

In each switch box, you have a black/white cable and a black/red/white cable. The black from the black/white cable should be connected to the common screw on each switch. The black and red of the black/red/white cables should be connected to the traveler screws on each switch. The white wires should be connected to each other in each box.

Is this what you have?
Old 08-18-04, 07:33 PM
Homer Simpson
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Three way switches controling a load from more than one location can only
function one way. The line must come into one switch and the load must
go out the other switch and you need 2 current carrying conductor connecting the switches together. usually a Red and Black.

1. You have the power coming in one switch.
2. You have a three conductor wire connecting one switch to another. Incidentally,the white wire is only there to provide a return for the load.
(Red, Black, and White with ground)
3. The White wires are all tied together all the way to the light bulb.
4 The Black wire carrying the power(line) is connected to the black screw
on the three way switch.
5. The Red and Black wires going to the other switch are connected to the
brass colored screws, it doesn't matter which one goes to which screw.
6. On the other switch wire it the same as in (5) and connect the Black wire
going to the light to the black screw on the switch.

Three way switches have three screws, 2 brass colored, 1 black colored.
Line and Load always go to the black screw.

For all you electricians out there, I know that there are other wiring configurations out there, But the above is really the proper way. eg.
line and load in the same outlet box. Say Goodbye, Homer. Goodbye

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