12V LED Lighting in Your Van: Wiring It Right the First Time

I've wired lighting in all three of my vans, and my biggest lesson was this: plan your switch and dimmer locations before you run a single wire. Nothing worse than having perfect lights but the switch in an awkward spot.

For layout, I split my van into zones: cab overhead, main living area, kitchen area, and bed area. Each zone gets its own switch or dimmer. This way I can have reading light in bed without lighting up the whole van. All zones share a common positive bus from one fused circuit — I run a 1.5mm² main line from the fuse box, then branch off with 0.75mm² to each zone.

Wiring topology matters. Always wire puck lights in parallel, never in series. In series, if one light fails, they all go dark — and the voltage divides between them so they'll be dim anyway. In parallel, each light gets full 12V, and if one fails, the rest stay on. For LED strips, they're already wired in parallel internally, so you just connect power to the strip ends.

Dimmers are where things get interesting. PWM dimmers work great with 12V LEDs — they rapidly switch the power on/off to reduce perceived brightness. Get a proper 12V PWM dimmer rated for LED loads, not an old resistive dimmer meant for halogen. I like the ones with a rotary knob and push on/off. You can find them for $8-15 and they install inline on the positive wire.

Fuse sizing: total up your maximum lighting load and pick a fuse about 50% above that. My whole van lighting draws a maximum of 2.5A, so I use a 5A fuse. Don't go crazy with a 15A fuse on a lighting circuit — the whole point is to protect the 0.75mm² wire, which can handle about 6A max before it starts getting warm.

One more thing — color temperature. Go warm white (2700-3000K) for living spaces. Cool white looks like a hospital. I learned this the hard way in my first van with 6000K strips. Swapped them out within a week.