Three way ?

Heyseed · Jan 6, 2018

Have a set of three way switches for a hall light in an older home. One works fine, the other only works if the first switch is in the on position. Did someone cross a wire when they wired this? I haven't opened it up yet, heading there tomorrow and thought I'd ask for ideas.
thanks.

David G · Jan 6, 2018

I would assume they are not wired correctly.

There are good diagrams on internet how to wire the three terminals.

old · Jan 6, 2018

Well has it always worked that way or has it just started to happen?? If always maybe wired wrong but if it just started good chance one or more switches is bad and or bad wire/connection

Janicholson · Jan 6, 2018

Look at the wiring (David G idea) Think of this: the white wire (neutral) is connected directly through the whole circuit and connects only to the light fixture silver terminal or white pigtail. The incoming supply wire is switched through double pole switches that allow a connection through a red wire, or a black wire. Either one of these is either connected through switch positions or open. The switch positions could be allowing current to flow through the red when both toggles are up, and through the black when both toggles are down, but through neither with one up and one down. Jim

dr sportster · Jan 6, 2018

The problem is called the point wire and a traveler are crossed. { This only can happen by someone changing a switch incorrectly.} In the case of a very confusing 3 way set-up the circuit can be turned off and an extension cord from another circuit is used to hot-up each conductor and identify. This is usually in cloth wire that has lost its color.

RayP(MI) · Jan 6, 2018

Be aware that all 3-way switches do not have the corresponding terminals in the same places. Replaced a switch a while back, connecting it exactly as the take out switch. Yup, didn't work! Took a bit of head scratching to get it working.

PJH · Jan 6, 2018

First of all - if one of the switches has "on-off" written on the toggle, it is not a three way switch. Of course you can easily tell this when you pull it from the box.

If you connect all three terminal wires in both switch boxes, the light should burn. That might point you to an incorrect connection in one of the boxes, or to a faulty switch. I've had three way switches fail and act exactly as you described.

Leroy · Jan 6, 2018

If it ever worked I would say first switch went bad.

Pete in MD · Jan 6, 2018

Have you verified that both switches are 3-way switches? All 3-ways should have 1 terminal marked Common or C. The hot wire from the breaker panel connects to 1 Common terminal and the hot wire to the light connects to the other Common terminal.

Is your set up wired like this? If it is, then 1 of the switches is bad.

jeffcat · Jan 6, 2018

First thing to check. Take the cover plate off on both switches. Both switches should have three screws. Two on one side and only one on the other. This is to see if the system was messed with. Next is put your rain boots on and jump in. Yes i knew someone who tryed to change a switch out and called and wanted to know what to do with the extra wire. Fun fun.

JDBRIDER · Jan 6, 2018

3-way switches do not have an off/on position. If a switch has an off/on position is not a 3-way.

olgentdc · Jan 6, 2018

correct ,..and is it still true you cannot make a 4 way switch ,..?

PJH · Jan 6, 2018

Ray, the common terminal usually has a black headed screw. It's the important one. The traveler terminals are not critical - if you switch them around, they only change the toggle position.

I'll bet you already knew that.

Andy Martin · Jan 6, 2018

(quoted from post at 18:46:34 01/06/18) correct ,..and is it still true you cannot make a 4 way switch ,..?

I can't understand this statement. Do you mean you can only buy them? When I rewired my shop I used four way switches for both rooms where I needed three switches to control the lights. If Home Depot has them they're pretty easy to come by.

Pete in MD · Jan 6, 2018

JDBRIDER,

"3-way switches do not have an off/on position."

The toggle on a 3-way has two positions. One position turns the power on and the other turns the power off. That makes it an on/off switch. (wink)

Pete in MD · Jan 6, 2018

olgentdc,

"..and is it still true you cannot make a 4 way switch ,..? "

No, that is not true. You can buy 4-way switches at HD, Lowes, Amazon, etc. They have 4 terminals and switch the 2 wires that are not connected to the common terminals on the 3-way switches.

Heyseed · Jan 7, 2018

Thanks for all the replies. I will open it up tomorrow when I get up there and see what is what.

Leroy · Jan 7, 2018

The power stays on, just goes to a different wire so it is still always on. And the way he described it is old switch quit working so has to be switch gone bad, not installed wrong.

rustyfarmall · Jan 7, 2018

(quoted from post at 11:28:46 01/06/18) Be aware that all 3-way switches do not have the corresponding terminals in the same places. Replaced a switch a while back, connecting it exactly as the take out switch. Yup, didn't work! Took a bit of head scratching to get it working.

Exactly!! I've made that mistake myself. It takes a bright light and a magnifying glass to see which terminal on the new switch is labeled "common". Most likely the common terminal on the new switch is NOT in the same position as it is on the old switch.

dr sportster · Jan 7, 2018

Same with a four way --- if it reads on and off it is a double pole switch and not a four way.

Pete in MD · Jan 7, 2018

Leroy,
My reply to JBRIDER was an attempt at humor regarding his use of "on/off". Did you notice the (wink)? If I had said "One position turns the LIGHT on and the other position turns the LIGHT off" would you agree.

In an earlier reply to the OP I told him if the switches are wired correctly then he has a bad switch. The OP indicated that he hadn't yet looked at the switches and wiring.

Brian G. NY · Jan 8, 2018

(quoted from post at 19:28:46 01/06/18) Be aware that all 3-way switches do not have the corresponding terminals in the same places.

I have run into that as well!

Three way ?

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