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Balfro 09-21-2010 10:59 PM

3-Way Switch Help
I am trying to install two 3-Way Switches that are more modern-looking where there used to be older 3-Way Switches. The first thing I noticed is that on the new ones the two screws on the one side is on the opposite side of the switch. Now, at first I thought to just turn the switch around but now the screw on the other side is at the bottom, where on the old ones it was at the top. I do not know if this makes any bit of difference at all.

I should also mention that the old ones did not have a ground screw, nor do the new ones.

I should also mention that the old switches did not have black screws, so this is where the confusion is mostly coming from.

Of course in all this "screws on the wrong side" business, I can't tell which wires go on which screws and all of the tutorials and videos that I can find online show the wall without any drywall on it so you can clearly see where the wires are going, etc. From inside the box it appears that the wires going from the second switch to the light fixture are going down from the box while the wires from the first switch are coming from the top, again, going against all tutorials I've seen.

SWITCH #1 has a black, red and white wire all going to/coming from the top of the box.

SWITCH #2 has a white wire capped off with another white wire going from the top to the bottom of the box. There's a red and black wire going to the top of the box and a black wire going to the bottom of the box.

No configuration I try is working, the best I can get is where one switch seems to allow the other switch to work, if you get what I mean.

Do I need different switches, cause where I bought them the guy said they were 3-Way and other than the differences mentioned above, they are pretty much the same as the ones that were in the wall to begin with.

I hope I described this well enough :confused:


budro 09-22-2010 05:27 AM

no matter what brand or design of a three way switch you have, there will be one odd colored screw on each switch. this is your common or "hot" wire. don't get confused because that hot wire is coming in one switch and going out the other. it just hops a ride on one of the two remaining wires to the other switch. keep it simple. first, make note of what colored wire went to this common terminal on the existing switches. if it is black then make sure you put the black wire on the "common" terminal on both switches. the other two are known as travelers and it doesn't matter which goes where on the remaining two terminals. unless a goof ball has wired them out of color sequence you should be ok. every once in a while i run into one where they made the red the "hot" wire, but 9 out of 10 times it's black. i did not try to dissect your post but just told you how a three way switch works. thanks for allowing me to help. budro

JoeD 09-22-2010 07:40 AM

Can you put the old switches back and make them work? If you can do it. Then change one switch. If you can't identify the COMMON then take a guess and put it on the black screw. Test the switches. If they don't work properly put a different wire on the common screw. It will only take three tries to get it working. The travellers don't mater.
Once you have one switch working properly replace the other one.

If you replace both switches at the same time there are too many combinations to get it working by guessing. Do them one at a time.

From your description the black wire from the bottom of SW2 sounds like it should be the COMMON in that switch box.

Balfro 09-22-2010 07:44 AM

Thanks for the reply, however I guess I was remembering it wrong (it's been a few months). It turn out in the old switches all three screws were on the same side. I will try to post photos later, but basically it looks like the white wire is attached to the HOT on switch #1...

Also no I was foolish and threw the old switches out long ago, the best I have is photos of how they were set up before.

Balfro 09-22-2010 08:46 AM

Here is the OLD switch #1:

Imageshack - photo1fm.jpg

And the OLD switch #2:

Imageshack - photojr.jpg

JoeD 09-22-2010 09:31 PM

Do you know which black in sw2 comes from the cable with only the white? That would most likely be the common. It would identify the common screw so you can find the common wire of the other switch as well.

Balfro 09-22-2010 10:07 PM

I have no idea. Based on the photos I'd say that it would be the one at the bottom screw on switch #2, right? I mean that does make sense, but I tried that set-up and it does not work.

See this is why I'm getting so frustrated, it appears my wire colors are messed up and nothing I try is working, lol. :(

But in your opinion, the white wire on switch #1 is the hot, right?

JoeD 09-23-2010 06:52 AM

Remove all the wires from the switches. Leave them hanging clear of the box. Turn the power back on and use a meter to find the one wire that has power on it. That wire goes to the common screw.

Turn the power off (leave it off) and short the other two wires together. Go to the other box and find the two wires that show shorted by using a ohmmeter. Those two wires at both ends are the traveller wires.

Balfro 09-23-2010 07:34 AM

Ok, that seems like it should work. I'll try that. Thanks.

hornetd 10-06-2010 09:01 PM

Well did it work?
Tom Horne

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