3 Way Switch Wiring Diagrams. Regardless of what 3-way switch wiring diagram youre following youll need to use a 3-wire cable to connect the two 3-way light switches. A 3-way switch wiring diagram is a simple drawing showing how to connect the wires to each of the four screws on the 3-way switch.
The electricity source and light fixture are connected to the same switch. Typical 3-Way Switch Wiring NM Cable In the 1st diagram below a 2-wire NM cable supplies power from the panel to the first switch box. This might seem intimidating but it does not have to be.
In this diagram power enters the fixture box.
There is a way to wire this but unfortunately it involves re-wiring at the light. Instead there is one 3-wire from the light box to each switch but nothing between the switches. The power wire the neutral wire and the traveller or switch wire. Regardless of what 3-way switch wiring diagram youre following youll need to use a 3-wire cable to connect the two 3-way light switches.