shows 8 (eight!!) different ways of wiring 3-way switches.
I am trying to figure out how the switches for our patio lights (two
separate fixtures controlled by the same two switches) were wired. Each
switch has two black wires and one red wire -- no white with black tape
at either switch. There are neutrals (several, wire-nutted together) in
each box, but they are not connected to anything else in the box. The
only configurations shown at the above Web site with no black-taped
white wires are Option 1 "Fixture Controlled by Two Switches: Power
Through a Switch Box" and Option 5 "End-of-Run Lights Controlled by Two
Three-Way Switches"; but I can't see what the difference is between
those two configurations anyway.
Any other possibility for 3-way switch wiring without black-taped white?
It would seem to me that option 1 and 5 are essentially the same
thing. The only difference I see is that option 5 has two lights
connected in parallel instead of 1 light. That is the most common
way 3 ways are wired and most likely what you have. It's consistent
with what you describe in your wiring.
And they ( the neutrals) _shouldn't_ be tied to the switches; only the
hot leg is to be switched.
What the others said re: layout; w/ 3-wire cable there's no need to use
the white as a hot; hence no tape.
The fundamental question is "WHY" and "WHAT" are you trying to do?
If you simply want a another light on the same switches, that could be
done by adding it in parallel to one of the existing ones w/o needing to
know the actual switch configuration.
If it's more involved, then you'll need to figure out which is the feed
and which are the travelers--that'll mean cutting the power and "ringing
out" the wiring or discovering by another means which is the actual feed
which may be deduce-able by looking at the arrangement--where is it most
logical to have power coming from w/ shortest cable runs from what else
is on the circuit?
Which John also asks. Are you just trying to understand how the circuit
works? Want to add to it? Doesn't work? Did it once work? Have you
disconnected wires? Do you have a meter or test light? Lightbulb(s) are OK?
At least you need to describe what wires leave the box in the same cable
or pipe and what those wires connect to inside the boxes. Romex or pipe?
In addition to the 3-ways shown in the link (all variations on the same
circuit) there is a "California 3-way", and old knob and tube might use
a "Carter" 3-way.
There is only one electrical or schematic topology for wiring a 3 way
switch . Hot wire from service to common on Switch 1, travelers on
switch 1 to travelers on switch 2, common on switch 2 to hot terminal
on load, neutral on load to neutral connection in service. All of the
other configuration are physical topologies meaning you can have wires
running all over the place but they better be like the electrical
topology. If you bring the service connection in at a switch, doesnt
matter which, the hot wire should connect to the common terminal on
that switch. If it connects in the middle the hot wire will connect to
a wire that goes back to the common on a switch. Dont just look at the
diagrams someone else drew, draw up what you have. Identify the wires
going from switch to switch, switch to lamp, etc. figure out which is
the hot and neutral coming from the service. Until you do this you are
*It sound as though you have a two wire line in one switch box and a two
wire load in the other box and a three wire between the two boxes. In this
instance 120 volts comes into one switch box. The white neutral of the two
wire is connected to the white of the three wire to carry the neutral over
to the next switch box. The black 120 volt hot wire gets connected to the
black terminal on the switch. The red and black of the three wire are the
travelers and get connected to the other terminals on the switch.
At the other switch location there is a two wire that goes to the light.
The white on the three wire gets connected to the white on the two going to
the light to carry the neutral up to the light. The black of the two wire
from the light gets connected to the black terminal on the three way switch.
The red and black wires from the three wire cable are travelers and go on
the other terminals on the switch.
If there are additional cables in the box with the 120 volt feed then that
feed is also supplying juice to something else.
I am returning to a problem I posted here 4 1/2 years ago under the
title "weird pilot light behavior." I couldn't find it again in Google
except where it was reproduced at:
Both 3-way switches (one in the house, the other in the garage) operate
the patio lights just fine, but I have been unable to understand the
behavior of the integral pilot lights. NB: *pilot lights," which should
be ON when the lights are on, OFF when the lights are off.
I had not realized until a few days ago that there are so many possible
configurations of 3-way switching. I posted my message here thinking
that my lights and switches might be wired in an uncommon configuration
that would explain the behavior of the pilot lights.
The switches are Pass & Seymour/Legrand TM83PLICC with integral LED
pilot lights. The circuit diagram shows one end of the LEDs connected to
a silver-colored screw labeled NEU and the other end connected through
resistors to each of the brass screws labeled 3W. There are also a black
COM screw and a green screw with the standard Ground marking.
I substituted these switches for the original ones that had no pilot
lights and added the connections from the silver-colored screws to the
whites in each box.
The pilot light of the switch in the house is ON in one position of the
switch, OFF in the other position of the switch, regardless of the
position of the switch in the garage. The COMmon of this switch is where
power is supplied to the circuit.
The pilot light of the switch in the garage glows dimly, irrespective of
the position of either switch -- except when there is no bulb in any
of the fittings.
The Pass & Seymour wiring diagram shows such a switch only at the point
where power is supplied to the system but a note says that the switches
can be used in both positions. HOWEVER, a message at
indicates that Leviton prescribes a different wiring arrangement when a
pilot light is required at the load-common position -- AND this requires
not only an additional conductor between the two switches but also
access to both of the pilot light connections (which the Pass & Seymour
switches do not provide).
Ooops! Make that "line-common"
-- AND this requires
*The wiring is the same for any three-way set up: A line on one switch, the
load on the other and two travelers between the two switches. In your case
you have an additional neutral requirement due to the pilot light.
Don't compare the P&S to the Leviton switches. The wiring requirements for
the pilot light are different.
You didn't mention if the one pilot light that works actually comes on when
the load is on.
I'm not sure what the problem may be. Some thoughts do come to mind: The
switches are not wired properly. One of the switches is defective. P&S
goofed and later found out from the field and customers such as yourself
that their product does not work as intended.
If you are sure that the switches are wired correctly I suggest giving P&S a
call and see what they have to say on this issue. I looked on their web
site and could not find any wiring diagrams.
The original is:
All the diagrams from your web link are wired the same (as John said).
There are just variations in configuration depending on where the feed,
switches and light(s) are relatively to each other.
There are a couple other ways to do it.
This is not the same description, at either the house or garage, as in
your old thread.
Your old thread said the switches illuminated correctly with
incandescent bulbs but work strangely with CFLs. The switch illumination
depends on one of the "3W" terminals at each switch being pulled down to
neutral potential when the patio lights are off. It is pulled down
because the terminals connect only to an incandescent bulb which is a
relatively low resistance to the neutral. That is not true with CFLs
(and is why a number of devices, like timers, don't work with CFLs). I
would guess capacitance between wires becomes a major effect in what is
happening. Replacing one of the lamps with an incandescent should make
the switches illuminate correctly. If you have a "dimming CFL" you could
try that - I don't know how they are different.
*I had the CFL thought in the back of my mind, but did not look at the
original post. That is most likely the problem. Another device
dysfunctional as a result of CFL use.
I disconnected all but the neutral and ground conductors from the switch
in the house, then touched the hot conductor to the two traveler screws
in turn. The LED illuminated in one case but not in the other. I popped
the rocker part of the switch and found that one of the connectors from
the LED unit was not making contact with its corresponding traveler
terminal. Once I remedied this deficiency all was OK.
White taped Black or no tape. I change the color on wires with tie-
Didnt realize you were trying to wire switches with pilot lights. Same
as a 3 way switch but they will not work unless you have bulb in the
socket. Dont know what effect CFCs have on them. This is why I said
look at it schematicaly. All you need to make it work is a couple of
neon bulbs across the travelers. As long as the switches are in an
off combination there will be current flow for the neon bulbs through
the load. Since this current is only a few milliamps it will light the
Neons and not the main lights. Dont expect the colors shown in the
diagram to be used. Hopefully the wires coming from the service panel
will have the right colors. I dont know much about the inner workings
of CFC's but it is conceivable that only one Neon may light at a time.
The off voltage of a incandescent lamp is less than 100 ohms which is
a short circuit for a Neon bulb. If the CF Cs have high enough off
resistance only one neon may light at a time, the one that fires
first.. Neon are also photosensitive lamps, in the light they come on
easier than lamps in the dark.
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