How to wire a 3-way switch with video

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.

3 way
3 way wire diagram
3 way switch wiring diagram
3wayswitch_wiring_diagram

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.

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45 thoughts on “How to wire a 3-way switch with video”

  1. Dominic,great video, my problem is power source is at the light 1st {along with two 2 other wires supplyiny power elsewhere–how do I set up 3 way form light ??

  2. 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

    1. 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.

  3. Great video and diagrams! I’m retrofitting the wiring around my home and this was a life saver. Thanks man!

  4. Enjoyed your video on the three way switch.
    Where I am still confused is…..isnt the wiring done differently depending on where the light is in relation to the switches?
    I mean, if there is the switch…then the light….then the switch….( light is between the two switches) isnt that wired differently than…..

    if there is the switch…..then the next switch……then the light…(light is at the end of the line)

    Hope that makes sense.
    thanks
    rich

    1. Yeah sure it makes sense. However it will stilled be wire from the switches the same way. But in this video I only show one of the ways to wire a 3 way. Check my other video “How to wire a 3 way to existing one way” That may help clean things up a little.

      1. I’m working in a home following someone else’s “beginnings”, relocations, wiring. It’s driving me crazy. Basically my problem at the moment…a wall was removed that had a 3 way switch on it, and the wire is in the attic now, but still attached to the other switch in the hall (it controls light on fan, and single pole in same gang box controls fan). The two switches in hallway were interconnected from a source (receptacle). I would like to get power back to the switch from the attic…my question is this, if I jump into a existing box in attic and only have black and white leads to connect to for power, what happens to my red wire going to the switch. I’m assuming I would tie the whites in with other white wires in existing box.

  5. 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.

  6. 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!

    1. 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

  7. Hey Dominick,

    Great videos, you give very good explanations in a simple manner easy to understand. I'm wondering if you could help me with something. In my bedroom, I have a light at the ceiling. Now, I have a first switch by the door that can turn the light on or off. I also have a second switch located by the bed that can also turn the light on or off, so that you could turn the light on as you walk in the room and turn it off once you're in bed. Only here's the weird part, when the switch by the bed is off, you can't turn the light on with the switch by the door. I wonder if it's a three way switch wired wrong or simple switches. I admit that I haven't opened the switches to see how it was wired. But in the case that those are normal switched, is it possible to replace them with 3 way switches with the existing wiring or do 3 way switches have to be thought of when the wiring to the light is done? Cause I really don't want to open my wall and do new electrical wiring.

    Thanks and great job on the videos!

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