Turn on the light or device being controlled by the 3 way switches if you already have them. In this video scott gives you a step by step instructional tour of how to wire and install a pair of 4 way switches in your wood shop.

Replace 4 Way Circuit With Ge Smart Switches
Replacing a 4 way switch. A 4 way switch has five terminals. One ground and 4 circuit terminals divided into two matching pairs called travelers. Fully explained 4 way switch diagrams. Then use a voltage tester to make sure that the circuit is dead. A three way switch connects travelers from that switch to one side of the four way switch while the other side is connected to the other three way switch and the three way switch is then connected to a light. The new switch has 4 terminals two on either side top and bottom.
Most 4 way switch wiring is placed between the wiring of two 3 way switches. Each pair of traveler terminals should be wired to the traveler wires from one of the 3 way switches in the circuit. 4 way switch wiring. Unscrew the switch from the electrical box and pull it out with the wires still. My old switch has two on top two on bottom. Turn off electric power.
It is important to understand how these switches are wired before attempting to troubleshoot or replace. Starting with safety and understanding 1. He will also explain how a 3 way circuit works. Guide to wiring a 4 way switch electrical question. The four way switch is not used on its own but in addition to a combination of switches. Unscrew and remove the switch plate.
To replace a four way switch follow these steps. 4 way switch configurations are used to control lights with three or more switchesa 3 way switch is used on each end with one or more 4 way switches in between the two 3 way switchesthey do not have an onoff position like single pole switches. Each of the two are one in front of the other. If the device is still. My old 4 way light switch broke so i bought a new switch and i am trying to connect the wires. Return to location you plan to wire to verify that there is no electric flow to that device.
The electrical wiring adds additional wiring to the same principles of 3 way switching. Turn off the power to the switch at the circuit panel or fuse box. When connected properly a simple flip of any of the switches will turn on the light. A 4 way switch must be wired between two 3 way switches as shown in the diagrams on this page. 4 way switches are a convenient way to operate lighting fixtures from three or more locations.