i'm going to be replacing a four-way
switch
make sure you always turn off the
electric to the circuit you're working
on
and double check it with an electrical
tester a shock
under the right conditions can be deadly
if you have three switches that operate
a light
you have a pair of three-way switches
and a four-way switch
the circuit is going to start with a
three-way switch
your four-way switch is going to be the
second switch
and the third switch going up to the
light will be a three-way
if you haven't removed your four-way
switch first turn off the electric
and then what we're trying to do is find
the matched pair of travelers coming
from that first
three-way switch this switch has two
screw terminals that are dark
in color and they have two screw
terminals that are light in color
the two dark colored screw terminals are
a matched pair
the two light colored screw terminals
are matched pairs this is very easy to
tell
what two wires are coming from the first
three-way switch
it also could have input or
output letting you know what's a matched
pair
this new four-way switch is kind of
unique it has
two raised areas that let you know that
these
top two screw terminals are a matched
pair
for this switch i would just mark two of
the wires that go to a matched pair of
screw terminals for example the top
two are going to the dark colored screw
terminals
i would mark these with a magic marker
or i'd put
tape on these two wires and now i would
connect
these two wires to either one
of the matched pair on the new switch
and now i know that this is going to
work with my other two three-way
switches
if you've removed a four-way switch and
you didn't mark the matched pair of
travelers
what you can do is turn off the electric
separate the wires so nothing's touching
and then turn the power back on and use
an electrical tester to find the live
wire
when you turn the electric on there's
only going to be one
live wire coming from the first
three-way switch
so i'm going to test the wires in this
case
this is the live wire so i know this
wire is coming from the first
three-way switch i don't know which
three-way
switch is coming from the service panel
and which is going up to the light
this switch is on the circuit so i'm
going to flip it in the other direction
and nothing changed so now i know
that this switch is going up to the
light so now i'm going to
flip the other three-way switch the
other direction
now that i switched the other three-way
switch this wire is dead
and this wire is live so i know that
these two wires are the travelers
coming from the first three-way switch
i'm going to mark
these two wires and connect them to a
matched pair of screw terminals on the
four-way switch
i turned the electric off i marked my
two wires and now i'm going to connect
them to the two screw terminals on the
new switch with the two raised areas
for this project i'm working in the
chicago area so we have metal conduit
connected to metal boxes
when i screw the switch into the metal
box it's going to be grounded our
conduit is our ground
path for most areas in the country
you're going to have
non-metallic cable with a bare ground
wire
that bare ground wire would be connected
to the green
grounding screw once you put the switch
in turn back
on the electric and then you can check
that all the switches are working