Wiring 12V Lights

DISCLAIMER: Working with electricity can be dangerous. I am not a professional electrician, nor do I have an extensive history with electrics. All the information provided has been gathered through advice and my own research and is specific to my electrical system.

main components for my 12v light installation


TOTAL: £77.18

Wiring up my 12 volt lights seemed like a really momentous occasion and a real milestone in the van build. 

I decided to go for a total of six lights, two either side each of my two vents and then another pair halfway between. I also found a touch sensitive dimmer switch to wire them up to. 

It’s important to wire up your lights in parallel - Not only does this mean that the power will be distributed evenly between each light, but it also means if one fails, the other five will continue to work as normal.

a 12v light taped to my roof

Crimping the LED Lights

The first stage was to crimp a male connector to the end of each positive and negative wire on each LED light. I bought wire connectors that had heat shrinkable covers to save me buying heat shrink separately. 

I crimped a male connector on each of the wires (twelve in total) and then applied heat with a heat gun to melt the covers in place. 

As I hadn’t fitted the cladding on my roof yet, I fixed each LED in place with some electrical tape.

Laying the Main Wire

Using the red and black 1.5mm cable, I crimped a female connector on the end of both the red and black cable, connected it to the furthest away LED light, and then fed the cables around the edge of the roof of the van, fastening it in place with electrical tape as I went. I’m going to position my dimmer switch just above where my electrical system sits, as this is close to my side door and my bed. I fed the cables all the way round to the point where the dimmer switch will sit and then cut the wire to fit. 

Joining LEDs to Main Wire

The next step was to connect each LED to the main positive and negative cable running round the roof of the van. 

To create a three-way connection I used T-Tap electrical connectors. These include a clip that snaps into place half way along the cable and digs a metal ‘tooth’ into the wire. You then crimp a male connector to the joining wire which fastens in place on the clip making a ‘T junction’.

I cut a length of positive and negative cable for each LED light and connected them to the main positive and negative cables running around the outside of the van using the T-Tap connectors.

Wiring to Switch and Fuse Box

close up of my fuse box with lights connected

The dimmer switch had a positive and negative input terminal and a positive and negative output terminal. I screwed the positive and negative cables coming from the LEDs into the output terminals.

Between the dimmer switch and the fuse box, I crimped ring connectors to the end of a length of positive and negative wires and then screwed these in place to my 12V fuse box, I then connected the other ends to the positive and negative input terminals on the dimmer switch. 

Lastly, I just needed to add a blade fuse to the connection on the fuse box. The wattage of each LED light was 2.5watts, making a total of 15 watts (2.5 x 6). 

If you remember Watts = Volts x Amps, I divided 15 watts by 12 (volts), which equals 1.25amps. 

A good way to size the fuse is to add 25% to the total amps of the appliance, so if you multiply 1.25 with 1.25, you get just over 1.50. You can’t get 1.5A fuses, so I used a 2A fuse for this connection. 

I don’t think I’ve ever been so happy to see lights turn on, but I’m pleased to say they lit up straight away and the touch sensitive dimmer switch works a charm!

If you have any questions at all, feel free to ping me an email or drop me a message on Instagram!