12v electric system in ford transit van conversion
My Van Conversion

Installing The 12v Electrics In My Van Conversion

14th May 2017

I have never done any 12v wiring or know of much knowledge to do with it, but surprisingly it was quite easy to do and I believe anyone can install a 12v system in any van conversion themselves with a little patience and internet research. Hopefully this post will help you with your personal 12v system.

My van needs to be able to sustain power being off grid for short and long periods of time while travelling round Europe, I will be wild camping most of the time so I won’t have access to main hookups for power but this is were having a solar panel and split charge relay helps.

Electric items used

  • 2x 230v Leisure batteries
  • 200 watts solar panel
  • 30amp charge controller
  • 3x 12way fuse boxes
  • 16mm red and black wire
  • 2.5mm red and black wire
  • Mains hookup kit
  • 1500w Power inverter
  • Split charge relay kit
  • Isolator switches
  • 7 Recessed spot lights
  • Smart charger

I planned roughly were all the electrics will be going at the start of the project, this is so I could run all the wires behind the walls and ceiling.

Over time I purchased all my electrical parts piece by piece and stored them in my box so when it came to installing the 12v electric system I wouldn’t have to wait for anything from the postman.

Box full of electrical goodies

Box full of electrical items.


Most of the electrics will be stored under the bed.

Layout of my 12v electric system that is stored under my bed in van conversion project.

Layout of electrics under the bed

  1. 2x 230Amp leisure Batteries (underneath other section of bed)
  2. Isolator switches
  3. 12 Way Fuse Box
  4. Split Charge Relay
  5. Pure Shine Power Inverter
  6. Mains Hookup
  7. Battery Charger
  8. Charge Controller
  9. Plug socket and 2x 12v sockets


12v electric system diagram in ford transit van conversion

12v wire diagram


leisure Batteries

Battery size (AH) is all personal preference but for me personally having BIG size batteries is a must so I can run all my appliances for a longer period time without the worry of them running out, especially as ile be off grid.

In my van I have two 230AH pleasure batteries, That is a Total of 460AH. For a lot of people this is way too much power if only using your camper van on weekends or short getaways. As I said before its all personal preference.

Both the batteries are stored under the main part of the bed and sit perfectly without any movement so there was no need to fix them to the bed or floor.

230ah leisure batteries under bed in van conversion

Both batteries fit under bed

Both positive and negative are wired together using 16mm wire and then connected to the 12way fuse box via a 30amp fuse and isolator switch.

12v electric system in ford transit van conversion

Batteries connected in parallel and then connect to fuse box on the control board.


12v electric system in ford transit van conversion

30amp battery fuse


control Board

The control board is where all the electrics in the van are connected to and have easy access for any problems, such as blown fuse.


12v electric system in ford transit van conversion

Control board. This is where all the electrics are connected.

Power Inverter

A power inverter is designed to convert 12v to 240v, this will allow me to power items with normal household plugs such as laptop, lamps or hairdryer. My power inverter has a rated power of 1500watts, this means it can’t run any appliance higher than 1500watts. The higher the watts the more expensive the inverter will be.

It connects straight to the 12way fuse box on the control board and the output is connected to a multiple plug socket. Having it connected to this enables me for future ideas/upgrades.

12v electric system in ford transit van conversion

12v electric system in ford transit van conversion

Plug socket and 12v sockets on side of bed


Mains Hookup/Battery Charger

The mains hookup will be barely used as the batteries will be getting charged most of the time from the 200watt solar panel on the roof, But its handy to have a mains hookup just incase I ever need it.

The mains hookup power inlet socket (waterproof) will be installed underneath the van but easily accessible, this is because I want the van to look slightly stealthy from the outside and I really don’t want to be cutting more holes in the vans.

12v electric system in ford transit van conversion

Mains hookup inlet socket installed underneath the van


12v electric system in ford transit van conversion

Mains hookup fuse box with sockets


The battery charger is always plugged in to the mains hookup so when I go to use the mains hookup the battery charger will automatically turn on and charge the batteries.

12v electric system in ford transit van conversion

Battery charger

Yes its upside down, but when you look at it from above its the right way up 😀

Split Charge Relay

The split charge relay is designed to charge my leisure batteries when the vehicle is running. It simply connects between the vehicle battery and leisure battery.

When the engine starts the relay detects the high voltage from the alternator and then starts to charge the vehicle and leisure batteries at the same time, when the engine turns off so will the relay because of the voltage drop, this way the vehicle battery won’t drain.

I purchased a cheap 30amp smart com relay kit off eBay but as its only 30amp so I purchased a 100amp relay also so I could get a higher ampage going through to the leisure batteries.

12v electric system in ford transit van conversion

positive and negative wire from van battery going through back of bed to smart com relay


12v electric system in ford transit van conversion

Wires go across bed to smart com via 20amp fuse


12v electric system in ford transit van conversion

smart com and 100amp relay

The wire from van battery connects to smart com and then connects to the 100amp relay and then to the two leisure batteries.


Extra Fuse Boxes

I have a fuse box under the kitchen cupboard that my powers the kitchen 12v sockets, water pump and plenty has room for plenty of room for future upgrades. This fuse box is powered from my leisure batteries.

I also have a fuse box inside the tall Cupboard beside the bed. This powers the tv and antenna. Again there is plenty of room for future upgrades.


I hope this post has helped some people who may be struggling with the electric section of your build or just given you some inspiration/ideas. As usual any questions please don’t hesitate to ask.












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  1. Reply

    David Bowman

    17th February 2020

    Instead of solar panels would I be able to hook up a generator with this system?

  2. Reply


    7th November 2018

    Quality conversion mate! I’ve got the same van and just fitted a ‘L’ shape bed/ seating. I’m struggling to figure out where to put my hobs and sink. How do you find it with your kitchen position with not being able to stand up?

    • Reply


      22nd November 2018

      Hello ryan, personaly i am use to the size of my van and not being able to stand up, this does not bother me. When i wash up and cook, i do it sitting down on the sofa/bed.

  3. Reply


    1st April 2018

    Thank you this is wonderful!!!! Thank you for putting this to together I don’t start my build for another month but I would love to knock on your door if I run into problems.

    • Reply


      4th April 2018

      Any problems please dont be afraid to ask for advice. Thanks for reading my blog :).

  4. Reply


    18th February 2018

    BLOODY BRILLIANT!!!! Thank you pal.
    I have been looking for a simplified and broken down explanation of how to wire a 12 system in a van.
    MASSIVE help reading through this.

    Well done on your van. It looks amazing.

    Lee – (Wales – Uk)

    • Reply


      4th April 2018

      Glad my post on 12v electrics has helped you with your build. Any more details you may need please dont be afraid to ask :).

    • Reply


      22nd November 2018

      Thank you very much. Im really happy knowing I have helped or inspired you in your build. Any questions dont be afaid to ask.

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Karl Norton

I have converted a standard Ford Transit van into a campervan to travel and explore the world wherever my heart desires.

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