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Old 01-30-2007, 12:02 PM
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SFBadger
Switches not working as three way

I have a pair of switches, one set at the entryway at the bottom of the stairs and one set at the top of the stairs that control the upstairs hallway lights. If both switches are on, the light is on, but if either swith is off or both switches are off, the light is off. Each switch has three wires connected to it.

Is there a way for me to test to see if I can re-wire the sitches to provide for real three-way operation? That is, switching one switch will turn the light on (or off) regardless of the position of the other?

Thanks.
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Old 01-30-2007, 08:58 PM
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three way switches are wired so that the line hot goes to one switch (odd colored screw) and the load goes to another odd colored screw at the other switch. the whites are spliced together and the other two wires goes to the other two screws left on the switch. I have multiple diagrams in the electrical "sticky" for three way switches. pick the diagram which closely matches your installation and follow it.
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Old 01-31-2007, 08:15 PM
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Thanks for the help, unfortunately, it's not turning out so easy. Sorry, I should have given more detail.

Unfortunately, this is a 1912 house, so I am not dealing with helpful coloring on the wires. Inside of each box, all three wires look exactly the same. Also, the switch terminals are all the same and are not labelled.

The way it seemed to work before I started removing covers and confusing myself is that switch 1 (at the top of the stairs) controls the power to switch 2 (at the bottom of the stairs), which controls the light. I actually expected to find two single pole switches wired in series, but I do have three way switches.

Soooo, I took an extension cord so I knew I was dealing with a proper ground, and tested the three connections on both switches. My coding system is as follows:

SW1=switch at the top of the stairs
SW2=switch at the bottom of the stairs
t1=terminal with no terminal on the opposite side of the switch (hot?)
t2=terminal on the same side as t1
t3=terminal across from t2 on its own side

Like this:
... __
t1 | |
... | |
t2 |_| t3

The switch is considered "UP" when it is on the side of t1, just like the picture above (one of my switches was installed opposite the other).

"H" means the terminal is hot, "O" means the terminal is off.

Here's what I got:

SW1....t1..t2..t3.....SW2.....t1..t2..t3......Ligh t
UP.......H...H...H.....DOWN....H...H...O.......OFF
UP.......H...H...O......UP.......O...H...O.......O FF
DOWN..O...O...O......UP.......O...O...O.......ON
DOWN..H...H...H.....DOWN....H...H...O.......OFF

So the only combination that makes the light turn on is when no terminal on either switch has any power runing through it. Huh? Trust me, I checked my measurements 3X.

Shouldn't there be a terminal on one of the switches that is always hot? Is there some knob & tube mystery that makes this more complicated? Should I give up on my dream of having three-way lights?

Thank you for reading this far.

Last edited by SFBadger; 01-31-2007 at 08:28 PM.
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Old 01-31-2007, 09:08 PM
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shouldn't really be a mystery with knob n tube wiring. even if the wires are the same color. at one box there has to be a hot wire. at the other there has to be a load wire. the other two are just the "travelers" with knob n tube there is no ground so finding the hot is a little more challenging. you can find the hot with a neon light tester and multimeter. shut off the breaker or open the fuse that serves those switches. take off both switches and leave the wires exposed. now re-energize the circuit. with your neon light grab hold of one prod with your fingers, now making sure you are not grounded, touch the metal prod to each of the three wires in one box and then the other. when you hit the hot wire, one side of the neon light will glow ever so slightly (orange) you won't feel a shock. this box is your hot box. now mark the hot with a piece of tape. splice the three together with a wirenut temporarily and go to the other box. now similarily with the test light touch each wire. two of the three should show hot. mark these - these will be your travelers. the one that's left is the load terminal to your light. now go back to the first box. de-energize the circuit and take apart the spliced wires. on a three way switch one screw is marked with an odd color, the hot goes here. the two unmarked travelers go on the other two screws. up at the other box, the two marked wires go on the bottom two screws and the load goes on the odd screw up here. re-energize the circuit and it should work as you desire.
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Old 02-05-2007, 02:23 PM
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HayZee,

Thanks for your help. Both sets of swiches are working as 3-way.
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