Before you begin anything with a three-way, you must understand that in order for you to have a three-way circuit you must have three-way switches. They are not the same as a regular switch at all. And a four-way is very different again. But that’s on a different page.
When most DIYer’s think of installing a 3 way their brain starts to melt. The fact is it’s very easy. You just need to overcome all those extra wires. Look at the diagram below. You’ll notice we now have travelers. These are the extra ones. But wait, your 3-way switch has two extra screws. So basically, you just need to add those wires to those screws and both switches. Yea it’s that simple.
3-way switch install
However on each 3-way switch, you have a black screw, this is the special one. On the power coming in from the panel, you would connect that black wire to the one black screw. And on the other switch, you would connect the black wire coming from the light to that black screw. The black and red wires in that 14/3 wire would connect to the other two screws.
You connect all white wires together in each box. But of course, the light itself will need that white wire (neutral) to power up. All grounds are tied together and connected to each switch in the box it is in.
Very simple, don’t you agree now.
![2017 NEC - Switch - Neutral Connections [404.2] (14min:30sec)](https://i.ytimg.com/vi/_no-E8ZOkfQ/0.jpg)
This is very easy and common how to wire a 3-way switch
If you have Lutron dimmer you might want to read this PDF file.
Comments ( 45 )
Hello
I have stared at your diagram and can’t figure out how to make it work for my set up. In my garage, power comes into a junction box in the middle of the garage. From that junction box a cable goes to the front of the garage where the switch is, another cable goes towards the back of the garage with several outlets daisy chained. These are what our shop lights plug into. The switch turns the outlets on and off. I wanted to add a switch to the back of the garage where the door goes into the house (so I can turn the lights on when i enter the garage from the house). If I replace the current switch to a 3 way, I understand I would need to connect the two 3 way switches with 14-3. It makes sense to me how to wire the switch in the new location, but what about the switch in the old location–it does not have power coming in one way and going to a light. Will I need to connect both black and both whites to the terminals (the ones coming from the junction box and the ones going to the 2nd switch?). I wish I could draw you a diagram, but your contact doesn’t allow me to attach a picture.
Thanks
Yes three ways switches on both ends. There are a few ways to wire a three way. Not just the way I show. This is the comment section of the page you’re on. Use the question section to where you can post pictures. Top right “Questions”
I enjoy your movies, and the way you explain things. I have a 12/2 wire running to my out building and I want to hook up a three way switch to my light,could you tell me how to do this, thanks.
Need to know more. Where is the light ? where is the switch ?. Watch my “adding a three way to a existing one way video”
Dominick, my son thought he would help out in replacing the old fashioned up-down toggle on-off wall switches to the new fancy large fascia switches. Here in lies the problem. He and his mom went and bought the wrong type switch. (was supposed to be a 3-way switch) This for two places where they control power to (1) a light in the middle of a long hallway and (2) a light controlled by switches at top and bottom of staircase. They made the change without me being present so I couldn’t figure out the original wiring connections. After burning up a few circuit breakers I put a stop to their effort as I was afraid they could have done worse. When I went back to try and re-install the original switches till I get the correct ones, I noticed the wiring to be different and am trying to figure out the proper way of re-connecting the wires to the on-off switches. The circuit to the hallway uses 2 red wires and 1 black wire. The circuit to the staircase uses two red and two black wires. In both circuits there are no white wires connected to any of the switches. Your help would be immensely appreciated.
Thanks,
George
Hi George, well without the proper testing of the wires to see what is what it’s really hard for me over the internet to help you. However watch my 3 way and 4 way switch videos. I’m they will be a big help.
Heya just wanted to give you a brief heads up and let you know a few of the images
aren’t loading properly. I’m not sure why but I think its a linking issue.
I’ve tried it in two different internet browsers
and both show the same results.
Thank you. Funny thing I was changing things on my site the same time you commented on this. They look good to me. I hope they are ok now?
I bought the switch yesterday from Lowes. The switch has “common” stamped on it where the dark screw is, so I know it is not a quality problem from the manufacturer. I will proceed with connecting my High to the dark screw, since you have seen this before. Thank you for your response and video.
Always my pleasure. Let me know how you make out.
My three way switch has the dark screw (common) across from a traveler and the other traveler at the bottom of the switch where the common is in your illustration. Is this a difference in brands of switches?
That would really depend. I’ve seen that before. And how old your switch is. I remember seeing some funky older switches before.
hey thanks for ur demonstration really help me alote ! im in trade school here in hawaii learning wana become an electrician but sometimes i dont get these instructors , but ur website and ur demonstrantion really help me alote . hope i can get some help from u to apply it in this field thanks .
Wondering what the difference would be when power source enters the middle switch. I understand the source and three wires using travelers as detailed in your video. So, I have three cables, two 14/2 and one three wire. I’ve connected source to the black and travelers as instructed as well as connecting the two white wires to each other. Now I have the two remaining wires from the cable going to the light. Where do I connect those? Do I connect the white with the other whites? Where would black be connected? Thanks for taking the time to share your knowledge in an excellent video!
Thank you. When you have wires in a box that I have no idea what they’re for it’s real hard to figure this out via these post. However, take both switches out. What wires do you have in the other box ? Let’s try this. Besides for travelers the whites / neutrals get tied together. The black screw would be one for power and the other switch for power out to the light. Or this could be all done from one switch having just the 3 wire running to the other switch.
So lets say the wires you have in box one are all of them. A 14/2 is power in, 14/2 is to the light and the three wire of course is to the other 3 way. Take the black wire from the other 3 way and connect that to the black wire to the light. And the wire from the light to the white from the power and the black from the power to the 3 way in the box with all the wires.
This should do the trick. Hard to explain without seeing it. Let me know
Would using 2 different switches matter? One is a reg switch on off and the other is a toggle. Would this make it not work right?
For a three way circuit it would. Both switches must be a three way.
Hi Ed. Thank you so much. It's always nice to hear.
Yes all grounds get terminated together and then grounded to the ground screw of the switch and the outlet or light fixture.