12v led lights with one plain switch and a 3 way switch.

Thread Starter

LemneJ

Joined Jan 21, 2020
4
I have 6 x 1.8 Watt LED spotlights to fit in the ceiling of my van. I am a COMPLETE novice but we all have to start somewhere! I am hoping to be able to use the wiring from the existing lights which I am removing but don't know if that is possible.

I would like to have 2 separate rows of 3 lights. I need two switches near the side sliding door one for the front set of lights (A) and one for the back set of lights (B). I also need a switch at the back doors just to operate the rear lights (B). I'm not sure which switches to get although I think I need a 3 way switch for (B) but not sure which one or if they are all the same. I also don't know which cables/wires to use and how to wire it. So that's just about everything I don't know really. I hope the drawing below shows what I need.
 

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Thread Starter

LemneJ

Joined Jan 21, 2020
4
I hadn't realised the picture had no backing so looked pants and didn't show what I meant. I couldn't edit the initial post so here it is again.

I need one on and off switch for the front lights (A) and 2 switches (one at side door and one at back door) for the back lights (B).




wiring drawing 2.png
 

Rich2

Joined Mar 3, 2014
134
You need 2 two way switches for the back lights with a 2 core cable between them. Just Google for a 2 way light switch schematic.
 

ebeowulf17

Joined Aug 12, 2014
3,059
When making choices on wires and switches, it's usually the voltage and the amperage you need to know, not so much the wattage. In many circuits, you can apply Ohm's law to calculate amperage from wattage and voltage, but LED fixtures often include a little circuitry of their own that obfuscates things.

Anyway, if you can look at the specs for your LED lights and find the amperage (maybe listed as current rating,) that will help with wire and switch selection.

It's been a while since I looked, but I'm pretty sure there are tons of 12V, 15A automotive switches to choose from. There's no way three of your lights draw anywhere near 15A, so you can probably use any of the common switches with that rating. The image shared by Hamlet above does a good job of illustrating how the three-way lighting wiring hooks up.

As for wire selection, there are numerous calculators online to choose appropriate wire size. You'll need to know the approximate length of the wire run (overestimate if you're not sure, just to play it safe) as well as the total current carried by each wire. Presumably that will be your individual light current times three, although if some of the wiring is shared for all six lights, then of course it's the total for all of them. Just plug a few numbers into an online automotive wire gauge calculator and it should tell you what size you need.
 

Dodgydave

Joined Jun 22, 2012
8,688
I hadn't realised the picture had no backing so looked pants and didn't show what I meant. I couldn't edit the initial post so here it is again.

I need one on and off switch for the front lights (A) and 2 switches (one at side door and one at back door) for the back lights (B).




View attachment 197407
Is this 12V or 230V mains,,??

A lights just need a Single way switch rated at the voltage, and B lights need Two Way switches, we can show you how to wire it easily..
 

Thread Starter

LemneJ

Joined Jan 21, 2020
4
Ok so choose 12V switches from an Automotive shop, or Caravan centre, that you like, and cable to suit length @ 3 Amp rated is plenty.

Here is a link to wire it two way.. Jump to 3.5mins for 2way..
I literally just saved this video on you tube! After trawling through all the vloggers it was nice to find a video that just explained what I wanted. Thanks for the advice :)
 
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