This circuit, two fixtures are shown but more can be added by duplicating the wiring arrangement between the lights for each one added.
Connect the black wire from the new cable to the common terminal on the second switch.
This black wire used to be attached to the old switch, and runs directly to the light.
First number specifies the gauge and the second number is the number of wires carrying current.
How wire a 4 way light switch
The black and red wires running between the switches serve as the travelers for the circuit.
If there is only one black wire, then the power is coming into the switch from the light fixture.
Three-way switches involve more cables, so you will need a little more room to work.
Common terminals will always be connected to a hot wire, either from the source or on the light fixture.
How wire a three way light switch
At the lights the white wire from sw2 is spliced to the hot terminal on each fixture.
If there are two black wires coming into the switch box, then the power is coming into the switch first.
The traveler wires are run using the other 2-wire cable between the lights and continue on to the traveler terminals on sw2.
This is located on the top or bottom of the switch, mounted to the frame.
Be re-marked black to indicate that it is a hot wire:Next is a circuit with the light between the two switches, but with the panel.
Connect the red wire on both ends of the new cable to the right traveler terminals on each switch.
A three-way switch allows you to turn a light on or off from two different switches.
Three-way switches are useful for large rooms with multiple entrances, but require a bit more wiring than a standard,.
Three-way switch allows you to turn a light on or off from two different switches.
Connect the black wire from the light to the black wire on the new cable in the original switch box.
It doesn't matter which traveler terminal is used for which traveler wire, reversing them should make no difference.
Now that both switches have been wired, you can screw them into the electrical boxes installed in the wall.
At sw1 the red and white wires from the 3-wire cable running between switches function as the travelers with the white marked for hot using black tape or paint.
Connect the white wire from the light to the common terminal on the first switch.
Connect the black wire from the power source to the common terminal of the first switch.
4 way switch must be wired between two 3 ways as shown in the diagrams on this page.
Each pair of terminals should be wired to the traveler wires from one of the 3 way switches.
You will likely need larger boxes than you already have if you are replacing a regular single-pole switch.
Here 3-wire cable runs between l1 and l2, 2-wire cable runs from the last fixture to sw1, and 3-wires runs between sw1 and sw2.
Wire screw - this is located on the left side of the switch, and is a different color than the two traveler terminals.