I just installed a pair of regular 3-way switches to control a ceiling
fixture between them. They replaced a pair of X-10 3-ways which had worked
but were no longer needed. The expected 3 wires came into each box; red,
black and white. The red wires were connected to the common terminals on
each switch, and the black and whites to the other 2 terminals; which ones
to which terminal shouldn't make any difference according to the
Problem now is that switch #1 has to be used to turn on the light and then
switch #2 can turn it on and off, but if switch #1 is used to turn the light
off, switch #2 won't turn it on.
Anyone got any ideas what's wrong?
You've miswired it. Hint: Switch #1 Common terminal has the wrong wire
on it. The common terminal will be a different color or tone than the
other two. It will not necessarily be in the same position as the common
terminal on the old switch. Since switch #2 apparently *doesn't* kill
the light independently of switch#1 position, switch#2 is wired correctly.
Specific colors mean nothing. Start from scratch. Remove switches from both
ends and separate the wires. One wire of one end only will be hot. It is the
common for that switch. Connect it to the switch and the two travelers as
well for that switch. Now go to the other location. One wire will be hot. It
is a traveler for that location. Now go back to the first location and flip
the switch. Now check the two remaining wires at the second location. One is
now hot. It is your second traveler for that switch and the last wire is the
Ah but there is. Were it miswired he would have discovered that when he
turned off the light with #2 he would not have been able to turn it on
with #1. He took pains to find that the reverse was true, so we can
assume that he tried it this way too. Draw out the circuit with both
switches miswired, and then with one switch miswired. Try every switch
position combination. Which matches his report? BTW, I'm an electrician,
I've had a few dealings with 3-ways :)
A miswired 3-way switch will in one position be able to kill the light
independently of the position of the other switch's toggle. In that
position, because the switch is miswired, the travelers are made
together by the switch, the (what was supposed to be common wire) is
wired to the wrong terminal. No matter where the other switch is
positioned or how it is wired it will not be able to send power to the
light fixture because the line is permanently open at the other switch.
If this argument applies equally to both switches, then both are
He has to turn it on with switch #1 to get any power to switch #2, which
means his common is transposed with one of the travelers at switch one.
Switch #2 only needs to be acting as a single pole for it to turn the light
on and off at that point, which means it too can have the common and one
traveler transposed as well
Thanks all for the suggestions. I understand now where the problem is and
how it has to be corrected.
I was led astray by the instructions in the package. They implied that the
wire colors for that kind of hookup were standard. I guess the guy who did
the original job 40 years ago didn't know that.
The instructions were wrong -- no such standards (that I know of). There's
quite a few different ways to wire up one of these, depending on where the
light is and where the power comes into the circuit, as well as what type
wire/cabling is being used.
You would need to give us far more info before anyone can "wire" it
correctly over the net.
You do realize that X10 is totally different when it comes to 3 way wiring
than regular switches.
X10 is masters and slaves where the slave just "shorts out" a feeder and
only needs two wires.
But there are X10 compatible switches that use the neutral.
but your regular 3 ways will need a different wiring configuration.
Thanks for the wake up call. The *X10* slid right by me. It's been
awhile since I did house wiring.
OP ignore my other posts, they apply to standard three way wiring
circuits. Yours can be rewired, probably at the fixture, but it won't
work as is.
SNIIPPED> > but your regular 3 ways will need a different wiring
don't feel bad.
I've seen professional electricians that have years of experience, that look
at any type of home automation stuff, and are totally baffled.
And they are right in front of it, not guessing from a usenet post
Get's really fun when someone has a problem with their bedroom light going
off or on, everytime they turn on the kitchen microwave.
Or if neighbors use the same system.<g>
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