Skip to Content

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

Affiliate Disclaimer: As an Amazon Associate, EXPLORIST.life earns from qualifying purchases.

Need Printable/Downloadable Camper Wiring Diagrams? Click Here
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.

Previous
How-to Size Fuses in a DIY Camper Van Electrical System
Next
How-To Wire Lights & Switches in a DIY Camper Van Electrical System


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

Robert Huffman

Saturday 30th of January 2021

Hi Nate. I'm currently designing my 12 volt circuits, but I have a question about this comment:

"I prefer running 1 x 12v outlet per fused circuit from the distribution block."

I want to have a lot of outlets throughout my van. The breaker box has room for only twelve circuits. Are you suggesting you prefer hanging wiring an outlet to each circuit that supplies another load? For instance, put an outlet on your fridge circuit, one on your fan circuit, one on your water pump circuit, etc.

Or, are you suggesting having one circuit dedicated to each 12 volt outlet?

Thanks for you help. Like many other people, I would be lost without it.

Nate Yarbrough

Monday 1st of February 2021

That comment might be a bit outdated as I've had time to experiment a bit with the best way to teach this stuff. Basically, you can use multiple outlets... but you just have to be aware of which ones may draw more power (say... a 12v electric air pump for tires or a paddle board) and know that you may not be able to run multiple high powered devices on one circuit. Although not a free resource, this guidebook shows how, and how many outlets can reasonably be on the same circuit and their max wattages: https://www.explorist.life/shop/solar-wiring-diagrams/12v-branch-circuits/

john k

Saturday 23rd of January 2021

hi nate

i purchased your wiring diagram "optional solar array...520W"

where, oh where, in the spaghetti of wires does the shunt go, please?

thank you again for the great information!

all the best

john kumiski

Nate Yarbrough

Monday 25th of January 2021

The shunt is between the battery bank and the Negative Busbar and is labled as "SmartShunt" on the diagram.

Chris

Monday 18th of January 2021

I am using mostly the 12ga duplex wire for my 12v accessories like you recommend. Is it ok to connect the 12ga wire with smaller wires (e.g. 16ga for fan, 22ga for lights, etc)? If so, what's the best way to do so?

Nate Yarbrough

Tuesday 19th of January 2021

To make those connections, you would use Lever Nuts. These (https://amzn.to/3sB5XWK) in particular can accept 2-5 wires of sizes from anywhere from 10 AWG to 20 AWG. These (https://amzn.to/3ipC9aJ) can connect 2-5 wires ranging in size from 24-12 AWG.

Martin

Wednesday 30th of December 2020

Hey Nate, I had a quick question. I’m planning on making a simple system in my van powered by a jackery 1000. I’m imagining connecting a distribution block to the jackery with the cigarette plug and this cord

https://www.amazon.com/dp/B01HGO2OIS/ref=cm_sw_em_r_mt_dp_Axo7FbVJ94DJQ?_encoding=UTF8&psc=1

Then lights (with switches) will connect to distribution block, and maybe a fan or other things down the road too. My question is, do I need a bus bar as well? Why or why not? Thanks for your time! I promise I looked all over your site before asking. Appreciate all the effort you put into making this resource!

Martin

Friday 1st of January 2021

@Nate Yarbrough, appreciate the response. Happy New Years and thank you again for the guides! This was the first place I learned about lever nuts and they look like they’re gonna come in real handy.

Nate Yarbrough

Thursday 31st of December 2020

You would just need the fuse block, not an additional busbar or anything.