4 Way Switch Wiring Diagram. In the diagrams below the first switch 3 way common terminal connects to line voltage. A 4 way switch wiring diagram is the clearest and easiest way to wire that pesky 4 way switch. Keep in mind that each light switch will count as two wires when calculating your box fill.
4 way switch wring diagram. Rear view of an old four way switch with copper screw terminals on one side and brass screw terminals on. A four switch configuration will have two 3 way switches one on each end and two 4 way switches in the middle. If you understand how to wire a 3 way switch you ll have no issues with a 4 way switch.
I have a few of the most common ways in wiring a 4 way switch to help you with your basic home wiring projects.
Free quick start guide here. This diagram is a thumbnail. Keep in mind that each light switch will count as two wires when calculating your box fill. One ground and 4 circuit terminals divided into two matching pairs called travelers. While some of the work being done will be with wires that cannot be carrying power yet there must.