12V RV 3 Way Switch Diagram: How to Wire a 12V 3 Way Switch

It is said that when you are hooking up switches, the wiring is the same for DC power as it is for AC power. That means that if you know how to wire AC switches and lights, you can wire DC lights and switches.

To wire a three-way switch, you just have to make sure you keep your wires straight. When you go to Amazon, you will find some uniquely designed 3-way switches. The ones you buy should all have 3 prongs on them. Then it is a matter of connecting the 3 wires.

To learn more about this process just continue to read our article. It has the information you want to know about so you can do this simple job easily. It is just a matter of connecting the right wires to the right prongs and making sure you have power to the switch.

12v 3-way Switch


All a three-way switch does is allow you to turn a light on or off from two different switches. These switches can be in two different locations in your home or RV. For example, one can be inside your RV and the other is outside.

These 3-way switches can be toggle switches or they can be regular light switches. The toggle has 3 prongs out the back while the regular light switches will have color-coated screws to attach the wires.

You are free to use any design you want as long as you have the correct amount of prongs and the wires connected in the right way. Also, these switches will come rated for a different number of amps.

When you are shopping you need to check the labels to make sure you are getting the one rated for your system. That means you will need to know the number of amps you will have running through the wires to your light, etc. If you are not sure which 3-way switch to buying, do not be afraid to ask for help.

Is There Always a Hot Wire On a 3-way Switch?

download (6)

Yes, there is always a hot wire for this electrical system. The black wire is considered the hot wire but it is also called the travel wire. There is a fourth wire in this system, a red one that is also hot and called a travel wire.

Both wires are considered hot but power only travels through one or the other, not both at the same time. But the red wire is not run from the power source to the first switch.

The red wire should connect to both the light and the other switch. As will the black wire. When you are connecting the white wires, they will not be connected to the switches in any way.

The neutral wire connects to the power source and the light. They will usually be spliced together in the wire boxes to create that uninterrupted return circuit to the power source.

But we are getting ahead of ourselves here. As long as you know the right wire colors, you will be able to wire these switches and the light together and bring yourself a little convenience. It just takes a little time.

How To Wire a 12v 3-way Switch


While it is simple, it can be a little complicated if you do not know the terminology or why you need 3 hot wires between switches. The first step is to run the white, ground, and hot wires from the power source to the first switch.

Depending on which 3-way switches you bought you either have 3 prongs on the switch or 4 screws to attach the wires between the switches and the light. You can put the light before the switches, between the switches, or after them.

That is not a concern as long as you have the right wires running and connecting where they should. Now that the black wire is connected to the first switch, you need 2 red wires going from the two outside prongs to the 2 outside prongs on the other switch.

The ground wire is spliced together and you may have 3 strands in one wire nut. The ground wire from the power source, one to the first switch and another to the second switch.

The second switch should also have 3 ground wires spliced and connected together in one wire nut. One from the first switch, one to the second switch, and one to the light.

The two travel wires must be connected at the same spot on both switches. If you use the top left screw for a regular switch or left outside prong then you must use the same ones on the second switch. A single hot wire will go from the second switch to the light.

That is the basic instructions to wire a 3-way switch. The diagram in the following section should make these instructions easier to understand.

12 Volt 3-way Switch Wiring Diagram


The diagram is fairly simple but be forewarned, there are different ways to align the 2 switches and the light. How you wire the system will depend on where the power source enters the setup.

Also, if you see a white wire with black tape on it, that is the hot wire. Different people will use different wire colors and colors of tape. One used black wire and red tape.


Some Final Words

This is not a hard project and DIY, handymen can have this done in an hour or two. It just takes time as you want to make sure you get the wires connected to the right prongs or screws.

Also, you have to determine where you want the power source to enter the system. Call a pro if you are not sure about all of this. They will help you.

Leave a Comment: