How to Wire A 3-Way Light Switch: 6 Steps You Must Follow to Learn


Is the thought of wiring an electrical switch in three ways sound intimidating. It’s not easy. However, following this guideline will allow you to be confident when working. Although it’s a bit more complex than simply wiring a standard single-pole switch, it could be relatively easy to wire a three-way switch once you clearly understand the wires you’ll need and how they should be wired up. The way you connect everything depends on the location your main line or power wires enter, whether they come through a switch box or an electrical fixtures box. As a licensed electrician, I’d like you to know that if you have any discomfort or difficulties during the installation of 3-way light switch wiring, please call an electrician in your area to complete the task. Read on to discover the best steps to wire a 3-way light switch!

What do you need to know about how to wire a 3-way light switch?

When you utilize a three-way switch, you’ll have two of them. This lets you manage the lighting of one or two lights in areas of your home. If you’re getting set to connect the wires, use the correct wire for the job! It is vital to ensure that before starting work, you make sure there is no electricity to the electrical wires you’ll work with. Electrical shocks are hazardous, and safety should be taken seriously! Most states also require that you be granted an electric permit to install the latest 3-way switch wiring, which will cost a few dollars.

See more: How to wire a 220 well pressure switch

Two styles of wire

The majority of homes are connected using NM cable. This is the non-metallic outer jacket that surrounds individual wires. NM is available in various designs, but for this particular job, you’ll only need to be aware of two types: the 2-conductor and the 3-conductor. You’ll likely come across the 12 or 14-gauge wire. In trade’, the cables are described by the following names:

  • The NM14/2 14 gauge wire has an outer white jacket that encloses 2 conductors carrying current as well as an earth
  • 13/3 NM 14 gauge wire that has a white outer jacket, which contains 3 conductors carrying current as well as ground
  • 12-2/NM 12 gauge wire, with an outer yellow jacket that houses two current-carrying conductors as well as an earth
  • 3/3 of NM Wire of 12 gauge with a yellow outer jacket, enclosed by three conductors that carry current.

In this tutorial, we’ll assume that you’ll be using 14 gauge wire, but it is possible to work with twelve gauges of wire.

3-way switch wiring methods

There are a few methods for bringing line power to your lighting. One option is to connect the power directly to the switch box. The alternative is to have the power flow to the lights first. Both are commonly used, and each has a unique way of conducting the wires routed through the switches.

Using pigtails

When wiring your switches, you’ll have to make what’s known as the “pigtail. It’s a length of wire approximately 6 inches long. It will connect to the switch and other wires using the wire nut. The National Electrical Code requires devices to be wired so that they will not interfere with the water flow if one needs to get removed. Pigtails make this feasible.

Choosing wire nuts

Wire nuts do not come in one size that fits all. It is essential to select the proper size to match the quantity and the thickness of the wire you use. Keeping some red and yellow wire nuts in your arsenal when working around the house is a good idea.

How to wire a 3-way light switch

Step 1

Determine the amperage and wire gauge needed to run your circuit. The amperage will determine the gauge of wire or wire you’ll require. This must be measured correctly to accommodate the amount of amperage or current passing along the wire. There are two standard household wires 14-gauge wire is appropriate for breakers with 15 amps. 12-gauge wire is suitable for a 20amp breaker. You can utilize wire over the current amperage capacity for the circuit breaker. However, you cannot make use of wire that is lower! It is crucial to keep the same conduction gauge throughout all circuits!

Step 2

Check for electricity on the wire you’re connecting using a voltage tester. Make sure to use one probe to connect to the other end on a wire that is hot and connect one probe on the ground wire. Your meter should read zero volts.

Step 3

Remove the cable jacket using a utility knife to cut through the insulation. Take care when cutting to ensure you don’t cut too deeply and cause damage to the insulation on the wires in question. The National Electrical Code requires 6 inches of conductor free from the time it is introduced into the box, and the wire should extend three inches to the outside of the container. So you will have to strip at least 6-inches from the jacket covering it.

Step 4

Cut off the ends of the individual wires to allow you to connect them together. Some will be connected to that screw on the switches, while others will join wires. This will determine the amount of insulation that must be removed. When the wire is connected to a screw, you’ll strip off about 1 inch of insulation to make an opening on the other end of the wire. Grab the end of the strippers or needle-nosed pliers.

Grab the wire’s end and twist it so that the wire’s ends can catch the screw. If the wire is to be wire-nutted with other wires, you’ll need to strip it off around 1/2 – 3/4 inches. Try to strip the exact amount from each wire. This will allow you to place the wire nut without the wire hanging out of the nut for the wire.

Step 5

The black 14/2 wire will connect to the screw with the dark common. The neutral white of this 14/2 will be connected to the neutral white of the 14/3, which is located through the switches. The ground of the 14/2 and 14/3 will be wire-nutted together using an oblique wire pigtail. The pigtail will be terminated in the screw green on the switch. The 14/2’s black wire emanating from the lamp will be hooked to the dark screw. The neutral of the white color of the 14/2 will be nuts to the white neutral of the 14/3, which runs across the switch. The ground between the 14/2 and 14/3 will be wire-nutted to a lengthy wire pigtail. The pigtail will be terminated on the green screw on the switch.

The 14/2 black line wire will be wired to the black wire of the 14/2 and then to the light switch that is the first. The neutral white connected to the line 14/2 is wired nuts to the neutral of 14/3 and a cable. The pigtail then connects to the screw that is silver in the light fixture. The red from the 14/3 will connect straight to the screw in the fixture, and after that, it will connect to the standard screw or the dark screw on the switching. The ground wires from 14/2 and 14/3 are connected with a Pigtail. The pigtail will be connected to the green screw of the fixture.

Step 6

If everything is in order, take off your time and apply electrical tape to the back of the switch to cover the screws and any exposed wire. This protects someone from getting a shock or wires coming in contact and shorting out. If you’re happy that you are satisfied, put the wires in the box, then mount the switch, and then place the switch cover on. When the cover is installed, you can restart the power.

Step 7

Check your switch by switching between the switches turned off and on. It is recommended to have someone else assist you in this means you don’t have to walk between the switch. For this, you must flip the switch, and another person will flip their switch. You will repeat the process three times before switching with each other. This confirms all electrical configurations the switch can perform. If the light goes off and on as it should, it’s accomplished, and everything is wired correctly. If a switch isn’t turning the light off or on, you’ve got your three-way switch wiring incorrect and must revisit and check the wiring.


Above we explain how to wire a 3-way light switch. Safety is the central aspect, so turn off the power before starting the work. Be sure to go at what you need to ensure you have the correct gauge wire. Also, you should know which wire comes from and its direction. This will ensure that you have the three-way switch appropriately wired. If you have doubts or are unsure if you are comfortable working on your project, make sure to call the electrician in your area, and they will offer an assist!

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