If you want to know how to wire a 3 way switch but can’t find a decent 3 way switch wiring diagram anywhere. Never fear, it’s really simple to do. All you’ll need are 2 SPDT- single pole double throw switches, or simply put, 3 way switches.

 

  • You’ll have 4 wires, the 2 connecting to the led and battery power are your “common” wires, and the other 2 connecting to the terminals, or loose ends of the common wires, are your “travelers.
  • Start by wiring the common wire of the first switch, this one should connect to the power source.
  • The common of the second switch needs to connect to the load.
  • Wire 1 traveler from the one switch’s terminal to the terminal on the other switch.
  • Repeat the process with the second traveler.

 


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ahuh

Joined: Jan 23 2012
Posts: 1
Post Mon Jan 23, 2012 4:01 pm

I am looking for a 3 way switch diagram for a car… something easy to follow. My application is to have a switch inside the cab of my truck for bed lighting, but also have one near the tailgate so that I can turn on the bed lights… thanks in advance for the diagram…

I have searched all over for this and can’t find it…

Aken

Joined: Feb 12 2003
Posts: 10885
Post Mon Jan 23, 2012 6:05 pm

That seems overkill for his situation, Venge.

I don’t see why you can’t just have two normal single switch applications, except both of the accessory wires go to the same lights. The worst thing you can do is create a loop of positive electricity if both switches are on at the same time. Unless that’s bad (I don’t think it is), it’s an easy setup that shouldn’t require relays or anything special.

bad venge

Joined: Jul 28 2007
Posts: 3550
Post Mon Jan 23, 2012 6:45 pm

You can backfeed and thats bad you can install diodes on both switches but I prefer the relay route
bugs825

Joined: Dec 24 2007
Posts: 81
Location: Florida
Post Wed Feb 08, 2012 1:11 am

Finally! One I can help with! I understand why you want to do it this way because you can turn the lights on at the bed then turn them off inside the cab. We did this same exact thing for my buddy’s truck. Its simple to do. Its the same concept as a hall light in your house that is using a 3-way system with 2 switches to control the lights, one switch at each end. Instead of using spst (single pole single throw) switches you will need spdt (single pole double throw) swithces AKA a 3-way switch. Radio Shack should have small ones that you can pick up pretty cheap. The wires that attach to the battery power and the LEDs is known as the “common” and the other 2 wires are “travelers”. These can be flipped at one end without any problems. They just allow the switches to work together to change the state (on or off) of the lights when either switch is flipped. If you think about what will happen in the pic when one switch is flipped it might help you to see how it works. You just need to make sure that the common is in the correct place on the switch.

Good luck and If I can help any more just let me know!

Nathan

CRAP! Cant upload the pic right now… I will try again in the AM![/img]

bugs825

Joined: Dec 24 2007
Posts: 81
Location: Florida
Post Wed Feb 08, 2012 6:47 pm

bad venge

Joined: Jul 28 2007
Posts: 3550
Post Wed Feb 08, 2012 6:58 pm

Sorry but the way it’s drawn will not work the way he wants

drawn you have to have the in cab on then switch the bed

he wants to hit either to turn on

bugs825

Joined: Dec 24 2007
Posts: 81
Location: Florida
Post Wed Feb 08, 2012 7:48 pm

I promise it will work. You need to remember that these are NOT SP (single pole) switches. They are SPDT (single pole double throw) switches.

Here is the above pic layed out

Cab switch – UP
Bed switch – Down
State – OFF

If you flip the cab switch you have this…

Cab switch – Down
Bed switch – Down
State – ON

Or the bed switch

Cab switch – Up
Bed switch – Up
State – ON

Its simple. If you change only one switch, either one. The state changes.

Nathan

I found a lame ass youtube vid that might help