Hi, I am Mark Donovan from HomeAdditionPlus.com and today, I am going to show you how to wire a three way light switch. One word of caution before starting any electro wiring in your home, make sure powers are turned off at the main circuit panel and check at the outlet or switch fixture itself with a multimeter or with a volt tester to make sure the power is indeed off before you begin working in electro box.

So as you can see here we have two switches and one light fixture. This is what we are going to call switch one, this is our light fixture and this is switch two. For a 50-amp circuit, we can use 14-2 and 14-3 wire. For a 20-amp circuit breaker, we can use 12-2 and 12-3 circuit wire. This is the 14-3 Romex cable that has not only a black and a white wire but also a red wire. This red wire is used for the traveler in our switch circuit today. The 14-2 wire just has a white and black. The black being your hot, your white being a neutral or return and then the bare wire being your ground.

The power coming in to the base of this box using 14-2 wire and we have the 14-3 wire being used between the switch boxes in the light fixture itself. What we have done is initially, we connect the ground wires together between 2-volts Romex cables. We twist them together and then attach them to the ground lock on the fixture like switch itself. We then take the black wire coming from the power supply or the circuit panel and we attach that to this black dark, which is known as the common wire on to the three-way switch. You notice this is a three-way switch. A two-way switch only has two connector contacts on it whereas a three way has a third contact.

We then take the black wire coming through the 14-3 Romex cable and attach it to the top right knot of the three-way switch. Likewise, we attach the red wire associated with the 14-3 wire coming from the light fixture on the opposite side of the switch, on the left hand side of the switch.

And finally we take the two white wires. One coming from the base 14-2 wire and the other wire coming through the 14-3, and we twist them together and put a wire from that on. Up with the light fixture itself, we have again one bundle of 14-3 wire coming in from switch one, and one bundle of 14-3 coming in from switch two. The first thing we do is we tie the two ground wires together. Just twist them together. They will normally attach to the light fixture itself on the ground. We then attach the two red wires together between the two bundles of cable. Third of all, we take the white wire associated with switch two and the black wire associated with switch one and we twist them together. And this is a very important step here, we put a piece of black tape on the white wire here as this white wire is going to be used as a hot wire. And finally, we attach the remaining black wire associated with switch two to one side of the contacts of a light fixture, and the white wire associated with switch one to the second contact of the light fixture.

With the second switch, we attach the 14-3 black wire that comes from the light fixture itself to a common — not on the three-way switch. This is the bottom right hand side of the switch. The white wire that became the hot wire at the light fixture comes in on that 14-3 and it connects to the top right knot. On the left top hand side of the switch, we attach the red wire again from the 14-3 wire coming from the light fixture, we attach that to the top left now. And then finally, we take the bare copper wire which is the ground and connect it to the green knot at the bottom left hand side of the three-way switch. And so with that, we connect these switches and light fixtures and test the circuit out.

So you can see, this three way light switch is working. It is a fairly complicated circuit. Hopefully, these instructions will help you. If you have any home improvement questions, visit us at HomeAdditionPlus.com today.