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How-to Wire 12v Accessories in a DIY Camper Van Electrical System

How-to Wire 12v Accessories in a DIY Camper Van Electrical System

The electrical system in a DIY Camper Van is a bit pointless if you don’t have anything to power, so let’s learn how to hard-wire plugs, fans, and other accessories into your camper.

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 Distribution Block

We already know that all positive wires need to be protected with a fuse. A 12v Distribution Block makes a nice, organized spot to make all of your accessory runs originate from:

12v Distribution Block

The 12v Distribution Block connects into your busbar and the one I like has enough spaces for 12 circuits and can power a max of 100 amps at a time combined between all the branch, or accessory circuits.

12v Wire Color

Power, Positive, and Hot (these all mean the same thing and can be used interchangeably) wires in 12v setups are typically red. Since you are likely starting this from scratch, I recommend keeping it consistent and going with red for the positive wires.

Negative and neutral (again, same thing) in 12v systems are commonly EITHER black or sometimes yellow. Keep it easy and consistant here and go with black for your negative wires unless you have a really good specific reason to choose otherwise.

Wiring 12v Plugs in a DIY Camper

12v Plugs will power any of your plug in devices such as camera battery chargers, phones, drones, and in some cases: Refrigerators.

Standard 12v Plug

On the back of the Standard 12v Plug, there will be 2 pins that you’ll attach your wires to with spade connectors.

Chaining Multiple 12v Outlets

If you want to chain multiple 12v outlets on the same citcuit, you’ll want to wire them like this:

If you decide to wire multiple 12v outlets in the same circuit, please stay aware of how many total amps you anticipate using in their ENTIRE cicuit and size your fuse and wire size appropriately.

I actually don’t like wiring multiple 12v outlets in series, personally. I prefer running 1 x 12v outlet per fused circuit from the distribution block.

Wiring 12v DIY Camper Van Accessories:

Most 12v Accessories can be wired using the exact same methods as described above. Fans, refrigerators, 4g booster, etc..

12v accessory wire

I’m a big fan of 12ga duplex wire for 12v circuits. It’s big enough for 95% of accessory circuits and when installed in lengths consistent with being installed inside a camper stays within the 3% voltage drop range even though, most of the time it isn’t necessary. It’s a red and black wire with high-grade, 105°C insulation contained inside of a white protective sheath

Now that you’ve learned how to wire 12v accessories and a distribution block, it’s time to learn how to wire lights and things that require switches.  In this next lesson we are even going to talk about wiring in 2-way switches so don’t miss it. Check that out here:

https://www.explorist.life/how-to-wire-12v-lights-switches-2-way-switches-in-a-camper/

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.


Steen @theunstealthy_nomad

Tuesday 16th of November 2021

What are your thoughts on splicing into the power that feeds the water pump? I want to add a 12v hard wired reading light and it would be a pain to try to fish the wire to the panel. An inline fuse is planned also. You have helped me out a few times already and I really appreciate it. Thanks so much.

Nate Yarbrough

Wednesday 1st of December 2021

Although not necessary 'best practice', it's 'likely fine'.

Basic Solar Parts Needed for a DIY Camper Van or RV Solar Install – webferocity

Saturday 25th of September 2021

[…] Step 13: How to wire 12v Accessories in to your system: https://www.explorist.life/how-to-wire-12v-plugs-fans-and-accessories-in-a-diy-camper/ […]

Tim de Reijer

Thursday 9th of September 2021

Hi Nate! First of all, hats off to all the informative blogs! I'm a bit puzzled however from the highlighted 'quote' on this page. It says "I actually don’t like wiring multiple 12v outlets in series, personally. I prefer running 1 x 12v outlet per fused circuit from the distribution block." Wouldn't you want to connect multiple sockets in parallel, if desired? (assuming we are talking about a 12v circuit)

Dustin Farrenkopf

Wednesday 26th of May 2021

Hey Nate! Awesome stuff. I purchased both high res wiring diagrams from you and they've been super helpful. But 8 do have a question about the Maxxair Fan hookup. In that diagram are you basing that from the model that has a motorized open function? It seems like that function draws the most power and thus a larger guage wire is required. I have 2 manual fans on a Ford Transit Extended High Roof) and am thinking that 14 awg would be plenty?

I'd love your thoughts.

Nate Yarbrough

Friday 18th of June 2021

Here's a wire size calculator if you want to stray from my recommendations on that one: https://www.explorist.life/wire-sizing-calculator/

Paul Cartwright

Saturday 3rd of April 2021

Hi have just picked up a 1986 vow t25. There is no 12v lighter socket or power output and I want the easiest way to wire one in. It looks like the distribution block is the original so there is only 4 outputs and they are all being used. Rather then replace this, could I split the cables that run to the fridge and wire a power output from that? Lazy I know. Tks Paul