Step-by-step for unravelling 3 and 4-way switches?

[beelzerob]

So, having now examined 8+ diagrams of how 3-way wiring might be done (let alone 4-way!), and having opened up both switch boxes and seeing a jumble of wires in there....I was wondering if anyone had a step-by-step detective like walkthrough of how to figure out what wire is what and how to change it from a 3-way to a single-switch arrangement.

I know there's a growing movement to using ALC here, so I was wondering if anyone has tackled this yet and what the steps would be to figure it out.

The alternative is to hire an electrician to do it. I'm not opposed to that, but unfortunately it's going to be several weeks from now at the earliest, and I want to install my light switches NOOOOOOOOOOOOW. <_<

 

[Sokoloff]

To take a 3-way out of the circuit, wire nut together the common and one of the traveler legs. (If nothing is labeled, you have a 2 in 3 chance of getting it right anyway, but with a neon test lamp, light up the load and see which one of the switch terminals ISN'T hot. Wire nut together the two that are (presumably, after turning off the circuit).)

That'll get you down to a single switch controlling the load.

 

[beelzerob]

"the common"...."the load"...."the traveler". *cry* When I looked in there, I swear it seemed like there were about 3 of each of those. (this 3-way is in a 2-gang box with ANOTHER 3-way switch).

I think my solution is going to be to take a pic of it and post it and we can identify stuff together!

At least the other switch in the 3-way was easier...all it had was the traveler attached to it.

 

[beelzerob]

Ok, here are two pics of the gang box in question.

The switch I'm currently interested in is the one on the right (although the one on the left is slated for replacement also).

It appears to be attached to 2 traveler (red) wires and a white (neutral I presume). The other switch in this 3-way is attached to a red, white and black.

So you're saying...wire nut together one of those reds to the white, then turn the power back on and see if the light is on? If so, then I've found the hot. Then use that hot (red wire) like a normal wired switch?

If so, then what do I do with the red, black, and white connected to the other switch in the 3-way?

 

[jmark71]

Just for posterity, and to help any others out... here are [post="71185"]diagrams[/post] that jdog (hope he doesn't mind me linking to his hard work here) posted in another thread... these are standard 3 and 4 way circuits without ALC and then wired with ALC...

BTW, for those who haven't already and are considering the OnQ ALC setup, a read of the complete thread is highly recommended - just give yourself an day or 7 to take it all in!!! It really is an excellent source of information...

 

[beelzerob]

Well, I saw those, and then a google search turned up even more variations...and I couldn't figure out which configuration mine was, without having taken out the light fixture too and looked at it. I figured there has to be an easier way.

 

[jmark71]

Well, I saw those, and then a google search turned up even more variations...and I couldn't figure out which configuration mine was, without having taken out the light fixture too and looked at it. I figured there has to be an easier way.

I figured you must have seen this, but thought it might be useful for some other folks... unfortunate timing of posts I think implied that I was referring to you. I appreciate the advice you gave me on my thread... but I'm certainly glad you're blazing the trail for others to learn from <_<

 

[beelzerob]

Hehe...well, I don't mind at all having more info put in this thread, hopefully to help others. But hopefully we can really help 'em by me showing them how to actually do it!

 

[Steve]

Personally I wouldn't start wire nutting things together to see what happens. I'd rather ring it out with a meter and know what it is first. Electricians often use the wrong color (like a neutral for hot). Most of the time they mark it like with tape or something, but not always.

 

[beelzerob]

None of these wires in the gang box are marked.

So, if the other switch in the 3-way only has the traveler wires connected to it, can I safely assume that the hot ISN'T there?

So what....power this back up and use my multimeter to measure what wires have +120v on them? But I'd have to remove the other switch first, right?

 

[beelzerob]

Ok, so I'm starting to get the idea...kinda.

So...if I go to the switch that only has the traveler in it....and turn the power on and find out which wire is hot. Then wire nut that wire to the wire connected to the "common" part of the switch....then that makes the OTHER switch a normal 2-way switch, right? I'd then go to that switch, disconnect the wire that no longer provides power (it's a dead wire now), and go from there?

 

[Sokoloff]

No, your first goal is to take the "remote" switch out of the HV picture, right?

So, open that one up, and with the power on, figure out what (two) black/red leads are hot. Then, flip the other switch (the one that's staying) and verify that ONE of those red/black stays hot and the OTHER one isn't. Wire nut TWO of those to each other, and cap off the third. (In other words, the one that was always hot, and your choice of the other, though I'd tend to choose black instead of red.)

Now, leaving the switches set such that the ones wire nutted together were both hot, test the switch that's staying. Mark/remember whichever of those two are hot and which one isn't. Remove the one that's not (will probably be the same color as the one you aren't using in the other switch) and now flip the switch. Whichever one stays hot is the "unswitched hot" (ALC black) and the other is the load (ALC blue).

(that's for 2 3-ways, no 4-ways)

 

[123]

Beezlerob,
IVB encountered the same problem two years ago. Here's my contribution and it includes step-by-step instructions.

 

[beelzerob]

Ok, here's the other switch: It's got a black and a white connected to it, and a red connected at the "common" connection.

Here's my measurement...and I don't know what to think of it.

Lights off: Red and black had 110V. White had 0.

Lights on (turned on via OTHER switch): Red and black STILL had 110V...and I swear that white did too. I know that doesn't make sense though. However, here's the weird part. When I measured the red and black, it shows 110v no problems...but when I measured the white, my multimeter beeped twice, and then read 75v. I tried several times, and it kept happening.

Either way, I'm certain that, no matter what the position of the other switch, this switch read 110v on the red and the black. The only questionable one was white, which definitely read 0 the first time, and then...I don't know...unknown the second time.

However, my little voltage detector safety gadget thingy pretty reliably detected the 110v's on the red and black wires also both times, and it ALSO beeped on the white wire once the light was switched.

So...hmmm.

thanks 123, I'll take a look at that.

 

[beelzerob]

Hmmm...well, I had hoped to be able to do this without taking the light fixture down too. Is that really the only way to know for sure? For some of these (the foyer light, for example) it's just not going to be possible.