Jun 02 , 2020
Wiring a 3-Way Light Switch
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.
With a pair of 3-way switches, either can make or break the connection that completes the circuit to the light. The whole wiring a light switch project can be completed in a few hours if you don’t have to do any drywall removal and repair.
Keep reading and learn how to wire a light switch. Also, use the 3-way switch wiring diagram to learn light switch wiring.
For a Visual Walkthrough of How to Wire a 3-Way Light Switch, Watch this Video:
Directions for Wiring a 3-Way Light Switch Yourself:
To add the switch, you’ll use one of two wiring a light switch diagrams (shown below), depending on whether the power comes to your light switch first (the most common situation) or to the light fixture first. Either way, complete these five steps for 3-way light switch wiring:
- Turn off the correct circuit at your electrical panel.
- Add an electrical box for the second 3-way switch in the basement.
- Pro tip: It’s likely you’ll also need to replace the existing switch box with a larger one to accommodate the extra wires for the 3 way switch.
- Feed a length of 14-3 type NM cable (or 12-3, if you’re connecting to 12-gauge wire) between the two boxes. The 14-3 cable has three insulated conductors: white, black and red (plus a bare ground wire).
- Connect the wires to the new 3-way switches with ground screws using one of the two wiring diagrams (Fig. A or B).
- Pro tip: The switches will be identified by a label on the common terminal and/or the terminal screw will be a different color.
- Make sure to wrap black electrical tape around the ends of all white wires used as travelers between the 3-way switches. If you have the setup shown in Fig. A, also wrap black tape around the white wire from the switch to the light.
- Pro tip: This way, you and others will know these wires are “hot” and not neutral like most white wires.