How-To Wire Lights & Switches in a DIY Camper Van Electrical System

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Ever live in a house that had lights you couldn’t turn off and on by a switch? No? Me either. Let’s keep that streak up. This blog post is going to teach you how to wire 12v lights (and any other 12v accessories) you want to control by a switch or two.

Quick note before we get started.  This is just one part of an overarching “How to Install a DIY Camper Van Electrical System” series.  If you’ve just stumbled on this article directly without seeing that, there are likely some things we’ve already covered.  If you want to check out that step by step guide, you can do that here: https://www.explorist.life/diy-campervan-solar

Also, we have interactive solar wiring diagrams that are a complete, A to Z solution for teaching you exactly what parts go where, what size wires to use, fuse size recommendations, wire lug sizes, and all kind of other stuff to help save you time and frustration.  You can check that out here: https://www.explorist.life/solarwiringdiagrams/

12v Light Switch

For a standard light switch, you’re looking for a switch that technically called “Single Pole Single Throw”, or commonly abbreviated “SPST”. This is the most basic switch. It simply has an on and off position:

12v Light Switch Wiring

On MOST 12v switches, it seems like most of them come with a little led indicator light on the actual switch.

If you want the little led indicator light to light up, you will wire the switch like this:

Me, I don’t want the indicator light to light up, so I’m going to totally omit the negative post on the back of the switch like this:

Want multiple lights on a switch? Great! You’ll be looking at wiring them like this:

If you want more light ‘zones’ and more switches, no problem! Just mirror that diagram down to the next fuse on your distribution block.

12v 2-way Switch

HUGLY POPULAR and somewhat confusing, but we will straighten that out.

The purpose of a 2 way switch is so that you can have a switch by your entry-way and another by, say, your bed so you can operate the lights.

It’s VERY VERY important you get the right switch. The switch you are looking for is a ‘Single Pole Double Throw – On/On’ 12v switch. Here’s how this switch functions:

As you can see, the exterior of the switch looks nearly IDENTICAL to the SPST switch we talked about earlier.

Here’s how to wire it up to lights:

Here is how the switch works in various positions:

Hopefully, you now know how to wire 12v lights and switches into your DIY Camper. If you have any questions, leave them in the comments below and subscribe for future updates.

Now that you know how to wire in a 12v switch and all of your lighting, it’s time for a lesson on how to figure out what size and type of wire to use in your DIY camper van electrical system.  Check that out here: https://www.explorist.life/what-wire-to-use-for-diy-camper-solar-system/

Everything that you are learning here is put to use in our FREE Interactive Solar Wiring Diagrams.  If you haven’t yet, check them out as they are a complete solution for a camper van electrical system.  Check them out here: https://www.explorist.life/solarwiringdiagrams/

Remember, this is just one part of a full camper van electrical educational series.  To see all of the individual guides, click here: https://www.explorist.life/diy-campervan-solar

Finally, If you found this guide helpful, It’d truly mean the world to us if you’d share it with somebody who can use it, pin it to pinterest for later reference, or share it to a facebook group when somebody has a question about this subject.  Click the bubble in the lower right corner to subscribe to be notified of future updates and as always, leave any questions you’ve got in the comments below.

47 thoughts on “How-To Wire Lights & Switches in a DIY Camper Van Electrical System”

  1. Hey Guys, these instructions are so great, Thank You!

    So here’s my question, for your Exterior LED Light Bar and Pods; Are those ran though the Chassis battery with a harness and relay, or though the house fuse box? Ideally I would like to have the front Light Bar with a dash switch, but my perimeter lights on switches in the back. What would be the best way to approach this?

    Thanks and keep up the great work, the updated site looks awesome.

    1. Ours are powered off of the house batteries. I haven’t covered relays and such on the site yet (2/26/19), but will get to it eventually. We have all of our lights on switches under the dash. The switches activate a relay in the back that turns on the lights outside.

      If I were doing it over again. I’d have a switch mounted up front that turns my light bar on only when my high beams are on. I’d also have a 2 way switch for each ‘zone’ of the peremeter lights, one switch under the dash, one switch in the back somewhere. Those would all activate relays that would turn the lights on.

      1. I haven’t purchased any solar equipment yet, so the numbers needed in your worksheet is null.

        My plan is to use renogy mono panels, 3-160W, all i have room for.

        The only items that will run 24 hours is an IceCo VL45 fridge/freezer.

        Most of my appliances are 120V which i have planned on putting (5…3 standard outlets and 2 GFCI)all 120V outlet, of course not use all the time..

        I’m not planning on any light switches, using “hand waved” puck lights via an adapter with plugs in with an adapter.

        What I need is: if correct…
        Size of mppt…100/40
        Pine SINE Inverter…
        …GoWISE Power PS1005
        1500w-cont/3000W Peak.
        Blue Sea Safety Switch…
        …Type?
        Busbar type?
        Fuse Box type?
        Etc…..
        I’ve purchased 12 gauge wire to wire 120V outlets, 3 on one side, so ponytail connections.
        2 outlets on other side, ponytailed as well. All wired back to fuse box.

        I plan on having Shore Power, have purchase wire 10 gauge (30amp).

        I have made a list of all my electrical (wants) laptop, printer, fridge/frz, coffee maker, etc. Most will be plugged in when use/unplugged when done.

        I would like to install an Isolator too, but solar first for I have only 3 months, then i wont have a place to so any building.

        I tried “jimindenver”, but he never responded. He was going to charge $500, but he’s never responded.

        3 months isnt alot of time

        Robert
        rp7313226@gmail.com

  2. Great info, thanks! Question Ford Transit 250 with standard LED interior lights. I interrupted the ground from each light to the switch you show, then grounded the switch seems to work fine. But after awhile it just shuts off. I know everything is on a loop, just want to make sure I am not damaging anything in the electrical system?

    1. No problem! Unfortunately, I dont know about your problem/system to accurately diagnose your issue. I can try again if you give me more info.

    2. Hello Bill,
      If I understood correctly, you have added a switch to the existing OEM interior light circuit and you haven’t disconnected it from the interior light power supply circuit.

      If this is the case you will need to isolate the circuit and provide a new power source with a fuse to prevent the the courtesy time delay of the interior light circuit. The only thing to note is that you will loose the ability to have the interior lights come on when you open the doors.

    3. Hi
      I have a transit van for work and most of the time I have back doors open and the tear interior lights start on for 30 mins then go off but come on again if I open another door
      How would I fit a switch or switches to the lights so I can turn them off during the day
      I have 12v 5050 led strip lights fitted
      Thanks

      1. You’d be looking for the cargo light circuit under the dash and installing an in-line switch there you could turn off during the day. I’m not sure where exactly you’d find that circuit but looking in the fuse box would be a good start.

  3. Great work on the info provided.

    I see you have wired the LED lights in parallel and am wondering if there are any issues if you were to wire in series creating a “loop” with the wire vs. what you show?

    1. Wiring them in parallel keeps the voltage correct. Wiring those particular lights in series will not work.

  4. When wiring multiple lights, you show a butt splice crimp connector with one (+ or -) wire of the light going into one end and two wires going into the other end. Are you just crimping both of those ends together into the butt splice connector?

  5. Hi Nate,

    Thank you for all this goldmine… I’ve been on it for the past couple weeks, many hours a day haha.
    I can’t figure out if I should wire the leds in series or parallel.. You show parallel but everywhere else I look I see people saying series is the way to go. I’m a bit lost here I must say… From what I understand parallel delivers the same power to each when series divides it.. So assuming power supply comes from the 12v box I should use parallel for the leds to work properly ? then size fuse and wire accordingly, and if I’m to wire in parallel, use these 3 way conductor connectors to link them ?
    Hope it makes sense,
    Much love all the way from France!

    1. Glad it’s been helpful! If the lights are 12v lights and you are powering them from a 12v source, they MUST be wired in parallel, else they won’t work.

      If the lights are anything other than 12v lights, 3v lights for example, you’d have to wire 4 lights in series for them to get to 12v; then you could wire sets of 4 lights in parallel.

      Long story short: just get 12v lights and wire them in parallel.

  6. Josh Etherington

    Great information. I was replacing a 12 volt light switch and noticed the previous owner had an additional brown ground wire coming off their switch but it didn’t appear attached to anything. The house 12V battery is grounded on the (-) wire (in this case a white wire) to the frame. The white wire goes from the switch (no led to avoid) back to the converter and battery (-) which is grounded. The hot or (+) wire is black and leads into the switch as well. So the additional brown wire seems redundant, so I’m assuming the brown wire was carry over before the battery was grounded or they added but didn’t need it. Does this sound right to you? And in your diagram it doesn’t say but the lack of an additional ground wire makes me believe you’re (-) is grounded on the (-) battery side?

    1. It would be similar. You’d want to add the dimmer switch to the wire that’s receiving power from the battery. It’s tough for me to speculate, though, what would happen if both of the switches were dimmer switches.

  7. Ahhh, this is so helpful! Going to be referring back to this when I get to the light installation. Thanks a heap! A great informative read.
    Cheers! 🙂
    Ryan

  8. Nate,

    Thanks so much for posting this, so helpful! I’m having trouble locating a spdt on-on round switch. Amazon lists on/off or on/off/on. Where did you find yours?

  9. Hey, is there a way to make the led light in the switch light up when the lighting is off so I can see the light switchin the dark? Thanks

  10. Nate I have been following this for a while and am now getting to my wiring. I want to install the SPDT on/on you describe above. This is a horse trailer conversion and most original lights are grounded to the frame at the light instead of running ground all the way back to the fuse box. Is this a wise thing to do? Will this work in this application?

    1. In that case you should look at some kind of remotely activated switching relay, probably controlled by some kind of Arduino unit. (it’s going to get quite a bit more complicated if you need 3 switches)

  11. Thanks for the write up! If you are wiring up the switches in two-way style, are you able to get the LEDs on the rocker to light up? I know you mentioned you don’t prefer for those LEDs to come on, just wondering if it was possible 🙂

  12. Hello I’ve wired up led lights in my van with a switch at the side door and switch at the back door on the 2 way switch but wanted to know how and if I can include another switch to the drivers side so I can control the lights from all 3 points independently thankyou

  13. I want to use the same DC branch from the DC distribution panel to have two separate lights and switches on it. Would I run the postive wire from the panel with 2 wire connectors to create a separate line to each switch then light? Then have a negative wire run back to the panel that each light would connect to for ground?
    With something like this: https://www.amazon.com/Nilight-Terminals-Self-stripping-Insulated-Disconnects/dp/B07CP987BN/ref=sr_1_4?dchild=1&keywords=wire+splice+connector&qid=1587437353&sr=8-4
    Or is there a better way?

      1. I was worried about that as I sent it. I don’t need a single line running from my dc fuse block/distribution panel for each individual light set with switch, right? I have 12 slots on my fuse block/distribution panel, but 14 different 12v things (sets of lights, outlets, weboost, water pump, etc). How do I double things up on one slot in the fuse block? You showed how to chain outlets on the wiring accessories page, but I want to stay away from chaining outlets due to higher amperage. I figure my led lights are very low amperage and could double up on a slot on the fuse block. How would I do that?

        1. I’m wondering the exact same thing. Is the answer to use a terminal block to wire all the lights together before sending them to the fuse panel? That or could you just use these splice connectors to connect them all?

  14. Hi. The ground of the spst switch is only to allow the LED to light up when switched on? If have multiple SPST switches for different accessories, can the ground of each switch be linked together to save me having to run many individual ground cables?

    Cheers

  15. Thanks for sharing the information and insights! I am hoping to wire two SPDT to six LED lights. Can a dimmer be wired “ahead” of the first switch? Thanks again!

  16. Hi this site is just amazing so thank you. So my question is I am linking led lights as per you diagram. Rather than run the neutral back to the fuse can I connect it to the switch neutral? Secondly what do you recommend to join the leds? The ones I have each come with a length of cable and are pre wired? Thanks

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