3-way wire question

Old 04-28-04, 11:23 AM
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3-way wire question

I have a light at the top of my basement staircase with a three way switch (one switch at top of stair, one switch at bottom) and would like to add another light at the bottom of the stair. The easist thing to do would be to wire the two light fixtures together but I cannot fish the wall of the existing light to wire them together. I can fish the wire from the switch at the bottom of the stairs to where I would like to add the fixture but am not sure that that would work. Here's how the existing wiring goes as far as I can tell. The 14-3 wire attached to the switch runs THROUGH a junction box in tact and goes to either the fixture or the switch at the top of the stair. The cable then returns to the junction box and attaches via wire nuts to the line wires. Can I add the fixture accessing only the switch at the bottom of the stair and the junction box or am I outta luck?

This sight is simply awesome!! Thank you in advance for any advice.

Old 04-28-04, 12:47 PM
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Ignoring "where" everything is for the moment, the idea of a 3-way switch is pretty simple. Power (black wire) connects to the common terminal of one 3-way switch, two "traveler" wires connect the switches, and the common terminal of the other 3-way switch connects to the light. The white or neutral side of the power connects directly from the power to the light, and does not pass through either switch (although the white wire might pass through the switch boxes along the way).

This site shows most of the physical combinations:

However my house has a situation that's not shown. It's like Option 1 on the web page, but with power coming in at the middle switch. 14-3 runs to the other switch, but they are all "hot" conductors, there's no neutral at that switch.

You need to understand how your wiring works, so you'll know whether you have suitable hot and neutral wires at the downstairs switch. If you're handy with a voltmeter or tester (and are appropriately careful) you can figure it out.
Old 04-28-04, 03:45 PM
Join Date: Sep 2002
Location: welland ontario
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You can normally attach the new in 2 places.
1. At the existing light.
2. At the switch that feeds the existing light.
I can't tell from your wire description where the line to the existing light goes. It could be that the wire to the existing light goes though the junction box you describe.

Is this cabling or conduit wiring? If it is conduit you should be able to pull more wires fromthe existing light to where you need them.

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