How to Wire Three-Way Electrical Switches

There are a lot of times that it would be convenient to have a switch at the other end of a room or hallway. To have a switch at every doorway entering a room just makes sense. Fortunately, there is a three-way switch designed to do that. All you have to do is wire a three-way switch at the two locations you would like to have a switch. Now you have the convenience of two switches that turn on the same light.

Things You'll Need

• 2 three-way switches
• 2-by-4 electrical box
• Switch cover
• Black, white, red, and green 12-gauge wire
• Screwdriver
• Wire connector
• Wire strippers (or knife and wire cutters)

Instructions

1. Find the breaker that feeds the light that you want to work on and turn that breaker off.

2. Mount the 2-by-4 box where you would like the new switch.

3. Run the black, white, red, and green wires from one switch box to the other. Leave 10 to 12 inches of wire hanging out of each box so that you have plenty to work with. Strip the insulation off about 1 inch of the ends of the wires.

4. Remove the switch cover on the existing switch and take the switch out of the box. It has two black wires on it. One black wire goes to the breaker you turned off in the panel box, and the other goes to the light. Before removing the wires, get a three-way switch out. The three-way switch has one screw on one side and two screws on the other side.

5. Take the black wire that goes to the breaker and connect it to the single screw on the one side. The other black wire should be placed with the black wire that goes to the new 2-by-4 box. Twist them together with a wire connector. The old switch can be saved to replace another switch in your home when it is broken. You still have two screws on the other side of the switch.

6. Take the red and white wires that are going to your new 2-by-4 box and connect those two wires to the two screws on the switch. It doesn't matter which one goes to which screw. Take the two green wires and put them on the green screw on the end of the switch. Screw the switch back into the box and replace the switch cover.

7. Take the other three-way switch to the new 2-by-4 box. Connect the green wire to the green screw on the end. This switch gets hooked up just like the other. Hook the black wire up to the single screw on one side and hook the red and white wires to the screws on the other side. It still doesn't matter which wire goes onto which screw. Now screw the switch into the box and put the new switch cover on.

8. Turn the breaker back on and you have a three-way switch system working on your light.

Tips & Warnings

• Wrap the ends of the wires clockwise around the screws. As you tighten the screws, they will wrap naturally around the screw. If you wrap them counterclockwise, they will want to unwrap as you tighten the screw.

• Electricity is dangerous. Turn the electricity is off before ever working on an electrical device.

References

• Lowe's