12V LED Lighting for Vans: Wiring, Dimming & Choosing Colour Temperature

Lighting is the cheapest thing in a van build and the one that most determines whether the finished space feels like a home or a service vehicle. It is also the only major system where the correct answer costs less than the wrong one — a well-planned 12V LED layout draws under 30W across the whole van, costs £60–120 in parts, and takes an afternoon. The mistakes are not technical; they are choosing 6000K white light because it was what the listing had, and wiring everything to one switch.

Why 12V LED and Nothing Else

Run lighting natively on 12V, direct from the battery through a fuse. Never through the inverter. A 20W lighting circuit inverted to 230V and back down through mains LED drivers wastes 15–25% of the energy and keeps a 2,000W inverter switched on all evening to serve 20W of load — which costs you another 8–30W in idle draw. The lighting itself becomes the smallest part of the problem.

12V LEDs are also efficient in absolute terms. A 12V LED strip producing genuinely useful light draws 4.8–14.4W per metre. Across a typical van — kitchen, seating, bed, entrance — total installed lighting comes to 25–40W, of which you might run half at any moment. Five hours of evening use is 60–100Wh, which is a small fraction of a 2,000Wh bank and the reason lighting rarely appears in power budgets as a problem.

Colour Temperature: The Decision That Sets the Mood

Colour temperature is measured in Kelvin, and it is the single most consequential choice in van lighting. Get it wrong and the van feels like a walk-in fridge regardless of how well it is built.

• 2700K (warm white): Domestic incandescent. Relaxing, flattering, correct for evening and sleeping areas.
• 3000K (soft white): Slightly crisper. The best all-round choice for a van interior.
• 4000K (neutral white): Office lighting. Useful over a work surface or in a garage area; cold everywhere else.
• 5000–6500K (cool white / daylight): Clinical. Marketed as “bright” because the eye perceives blue-heavy light as brighter at the same wattage. Wrong for living space.

Fit 2700K or 3000K throughout the living area. If you want cooler light over the cooker or a workbench, run that as a separate circuit rather than compromising the whole van. Mixing colour temperatures in one visible space looks like a mistake even when it is deliberate, so keep the split clean and physically separated.

CRI matters more than most people realise. Colour Rendering Index measures how accurately a light source shows colour, on a scale to 100. Cheap LED strips run CRI 70–75, which makes food look grey and skin look ill. Anything above CRI 90 renders colour properly. The price difference is roughly 30%, and it is the difference between a van that photographs well and one that does not. Listings that do not state a CRI figure are almost always below 80.

Strip, Puck or Spot: What Goes Where

LED strip

Flexible tape, cut to length every 50–100mm, self-adhesive backing. Perfect for indirect lighting hidden behind a batten or above a cupboard, where you see the light and not the source. This is what makes a van feel finished.

Buy the 12V variety, not 24V, and check the density — 60 LEDs per metre is standard, 120 per metre gives smoother light with no visible dots when the strip is close to a surface. Choose IP65 for anywhere near a door, sink or window; IP20 is fine elsewhere and stays brighter without the silicone coating.

The adhesive backing on cheap strip fails within a year in a vehicle that heats, cools and vibrates. Run a bead of clear silicone or use aluminium mounting channel — the channel also acts as a heatsink, and LED strip that runs cool lasts several times longer.

Puck and downlights

Recessed 12V pucks give focused pools of light for reading, cooking and finding things. Typically 1.5–3W each. Fit them where a task happens rather than spacing them evenly across the ceiling — even spacing is a house-lighting habit that makes a small space feel institutional.

Spotlights and reading lights

Directional, switched individually, mounted at the bed and seating. These are what you actually use most evenings, and having them on their own switches is the difference between reading in bed and lighting the whole van to do it.

Awning and exterior

One 12V exterior light by the side door, on its own switch, is worth fitting during the build and impossible to add tidily afterwards.

Wiring: Circuits, Fusing and Cable

Lighting is low current, so cable sizing is undemanding — but the circuit design matters more than the wire.

Split lighting into at least three circuits: main living, task/kitchen, and bed/reading. Each on its own switch, each fused separately at the distribution panel. One switch for everything is the most common regret in a first van build, because it means the only way to get light at 3am is to flood the van with it.

Practical wiring for a typical van:

• Distribution panel to each lighting circuit: 1.5mm² cable, 5A fuse per circuit
• Total lighting load: typically 25–40W (2–3.5A at 12V), so a single 10A feed serves everything
• Keep runs under 5m or step up to 2.5mm² — at 12V, a long thin run visibly dims the far end
• Use crimped and heat-shrunk butt connectors, not twisted joints or chocolate blocks

The wiring principles are the same as the rest of the system, just at lower current — the full cable and fusing tables are in the van wiring and electrical safety guide.

Dimming: Do It Properly or Not At All

Dimming transforms a van interior, and it is where most people get poor results. There are two methods.

PWM dimmers switch the LEDs on and off very rapidly, and the ratio sets the brightness. This is the correct method for 12V LED, it does not shift colour temperature as it dims, and units cost £8–20. The catch is switching frequency: cheap dimmers run at 100–500Hz, which produces visible flicker in peripheral vision and shows up as banding on phone video. Buy a dimmer specifying above 1kHz — most people cannot consciously see the flicker below that, but plenty get headaches from it.

Resistive dimmers waste the difference as heat, get hot, and shorten LED life. Avoid them.

Fit rotary dimmers rather than touch-sensitive ones. Touch dimmers fail with wet or cold hands, which describes van life accurately.

Switch Placement: The Part Nobody Plans

Switch positions are decided during the build in about ninety seconds and then lived with for years. Two rules cover most of it.

Every light you use in bed needs a switch you can reach from bed. Obvious, routinely forgotten. The reading lights want individual switches on the light itself, and the main circuit wants a switch within arm’s reach of the pillow so you are not crossing a dark van to turn everything off.

Every light you use on arrival needs a switch by the door. Coming back to the van in the dark with wet hands and shopping is the moment lighting either works or does not. One switch inside the side door that brings up the ambient circuit solves it.

That implies two switch locations for the main circuit, which means either two-way switching (two switches, either one toggles the light — the same wiring as a domestic stairwell, using two changeover switches and a three-core run between them) or a latching relay. Two-way switching costs about £6 and thirty minutes, and it is the detail that makes a van feel properly built rather than assembled.

Fit switches with a small illuminated indicator so you can find them in the dark. The indicator LED draws around 0.02W, which is nothing, and it removes the nightly hunt along a wall panel.

Real Power Draw and What It Costs You

Measured figures for a typical installation:

• 3m of 60-LED/m warm white strip: 14–18W at full brightness
• Six recessed pucks at 2W: 12W if all on, rarely the case
• Two reading lights at 1.5W: 3W
• Exterior light: 3–5W

Whole-van installed capacity: 32–38W. Realistic evening usage: 12–20W for four to six hours, so 60–110Wh per day in winter when darkness arrives at four, and 25–40Wh in summer.

Put that against a compressor fridge at 400–500Wh per day and lighting is a rounding error — provided it stays on 12V. Run the same lights through an inverter and the inverter’s idle draw alone can exceed the lighting load four times over. This is the single reason to get it right.

Three Lighting Plans With Costs

Minimal — £45–70

3m of warm white strip in aluminium channel above the units, two reading lights, one switch each. Draws 18W all on. Adequate, and better than most factory conversions.

Standard — £90–150

Strip lighting on a dimmer for ambient, four recessed pucks over the kitchen on a second circuit, two reading lights on individual switches, one exterior light. Three circuits, four switches. This is the layout that suits most vans and the one worth planning around.

Full — £180–280

All of the above plus dimmable circuits throughout, under-cabinet task strip, floor-level night lighting on a separate low-output circuit, and a switch panel by both the bed and the door so you can kill everything from either. Adds perhaps 8W and a great deal of usability.

Four Mistakes You Only Make Once

Buying 6000K because it looked brightest in the listing. Cool white makes a small wooden space feel like a mortuary. 2700–3000K, every time.

One switch for the whole van. Three circuits cost about £15 more in fuses and switches and are worth more than any other £15 in the build.

Relying on the strip’s own adhesive. It will let go in the first hot summer. Aluminium channel or silicone, always.

Wiring lighting through the inverter. A 20W load keeping a 2,000W inverter awake all evening is the most expensive lighting decision available.

Verdict: 3000K, Three Circuits, Proper Dimmer

Fit 2700–3000K LEDs at CRI 90 or better, split across at least three switched circuits, wired natively on 12V at 1.5mm² with a 5A fuse each, with a PWM dimmer above 1kHz on the ambient circuit. That is £90–150 of parts and an afternoon’s work, and it does more for how the van feels than anything else at that price.

Because the whole installation draws under 40W, it works on any power system — including a portable one. A Bluetti AC200L running lighting from its 12V output uses roughly 5% of its capacity across a winter evening, and a Bluetti Elite 200 V2 does the same. Either way the point holds: take lighting from the 12V output, never from the AC socket, or you spend more on inverter idle draw than on the lights themselves.