Two very old three way switches. 3 way switch schematic wiring diagram.

How Three Way Light Switches Work
3 way circuit wiring diagram. As you will see most 4 way switch wiring is placed between the wiring of two 3 way switches therefore a 4way switch is installed with two 3way. Typical 3 way switch wiring nm cable. 3 way switch wiring diagram. Wiring multiple lights on a 3 way switch. With these diagrams below it will take the guess work out of wiring. With a pair of 3 way switches either can make or break the connection that completes the circuit to the light.
Take a closer look at a 3 way switch wiring diagram. Assortment of fender telecaster 3 way switch wiring diagram. This is only a wiring schematic and not the actual wiring method used for 3 way switch installations. It shows the elements of the circuit as streamlined shapes and the power and also signal links in between the devices. Below is a simple 3 way schematic that can be applied to all three way electrical light switch connections. If more than three switches are needed simply place more 4 way switches between the three way switches.
Pick the diagram that is most like the scenario you are in and see if you can wire your switch. The black line wire connects to the common terminal of the first 3 way switch. 4 way switch wiring 4 way switches provide switching from three or more locations. Three wire cable runs between the switches and 2 wire cable runs to the light. This might seem intimidating but it does not have to be. A 3 wire nm connects the traveler terminals of the first and second 3 way switch together.
To illustrate the wiring of these 3 way switches switch boxes and fixture boxes are not shown but are obviously required for every application. Wiring a 3 way light switch. Traveler wires are interchangeable. The basic 3 way switch wiring diagram this is the most common and the easiest wiring diagram to follow of any of the wiring diagrams for a 3 way switch circuit. The steps above describe installing a 3 way switch and provide a 3 way switch diagram utilizing one light fixture. Wiring diagram 3 way switch with light at the end in this diagram the electrical source is at the first switch and the light is located at the end of the circuit.
Wiring a 3 way light switch is certainly more complicated than that of the more common single pole switch but you can figure it out if you follow our 3 way switch wiring diagram. The travelers actually pass the electricity between the two 3 way switches as well as the 4 way switches shown in the 4 way switching wiring diagrams. This wire diagram shows the wiring for source power into the first three way switch then 3 wire cable to the next 3 way light switch and then on to the light or light fixtures. If you intend to add multiple lights with a 3 way switch use the 3 way switch for multiple lights diagram. Two very old three way switches are depicted in the photo above. In the 1st diagram below a 2 wire nm cable supplies power from the panel to the first switch box.
A wiring diagram is a simplified conventional photographic depiction of an electric circuit.