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 )
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!
Dominick –
Thank you for the diagrams. One minor correction: In the top diagram – the diagram where the switches are labelled S1 and S2 – the wiring to the bulb is backwards. For safety, the hot wire should always go to the tip of the bulb, and the neutral to the threads of the bulb.
MT
Thank you so much for pointing that out. I have fixed that. I didn’t make the picture but I sure fixed that.
ok so im just changing switches with new ones. did it one wire at a time so i didnt get wires mixed up. didnt work. i found your video. big help. now i see what my problem is. i have a 2 wire and a 3 wire in the first box like you said. black and white coming in. black white and red going to the other box. but no other wires going to the light? in the first box they have the incoming white and outgoing red together? incoming black to black screw. outgoing black and white as jumpers? how does that work? only thing i can think of is they either have a junction box in the attic or it works off the light somehow. i just had surgery so i cant get my ladder out to look. any ideas?
Mr. Dominick,
I understand the basic wiring for a 3-way switch and your video helps to reinforce my understanding. My wife asked me to install new LED fixtures in the hallway. One is on a separate 2-way switch (works fine) and the other is connected to 3-way switches. However, I seem to be getting residual/inductive current; the fixture glows when switched-off. The power seems to be coming into the light and running into the switches. I can’t seem to segregate the residual current to keep the light from glowing. Any ideas?
It sounds like one of the switches is not wired right to where you’re allowing a low voltage to go to the light. A led as you know uses very little electric and just a little will give it some light. First make sure you wired the light correctly. Meaning the hot is on the hot side. Although the wires may be the right colors but it doesn’t mean they are right. Try switching them around maybe. And make sure if you have a ground on the fixture that it is connected.
Great video and diagrams! I’m retrofitting the wiring around my home and this was a life saver. Thanks man!
Hi I wouldn't think you'll find a junction box. I would start all over again and trace out each wire to see what they are and where they are coming from.
Hi Dominick, How would I wire 2 lights to 2 3 way switches? I have a light at the top of the stairs and a light at the bottom of the stairs. So i want to put a switch at the bottom of the stairs and at the top of the stairs. Thanks
Each light would just come off of each other. But watch this video. It should help. https://www.askmediy.com/how-to-wire-a-three-way-switch-to-a-existing-single-pole-light-switch-circuit/
That is a great idea for a video. As soon as I can I make one. Thank you for your input. The easiest way to do what you want would be to install a remote control in the light. Otherwise you'll have to run a new wire from the switch to the light with a extra hot, known as a /3 wire.
Thank you very much for your video on how to wire a three way switch. Very helpful
Joe
Always my pleasure
Hey Dominic! – Quick question about your 3way switch wiring – I don't understand where the grounds go? Do ya take both of them and screw both to the green grounding screw on the switch or do ya wire nut them together and put them somewhere else? Can you help me out? BTW, thanks for youtubing! I've done SOOOO much around my house because of what you taught me through your videos. Saved a TON of money. Thanks again boss! Ed