Trailer Number Plate Lamp in a Premium Specification

Trailer lighting: the lamp that is always broken on a second hand trailer, and the one an officer will notice.

Towing is the one thing you can buy for a car where the wrong part is not merely disappointing. Every towbar listing here states the type approval number, the D value, the maximum noseweight and whether the bumper has to be cut, because those four facts decide whether a bar is legal on your vehicle and whether it will pull what you want to pull. Every electrical listing says plainly whether it is a dedicated loom or a universal one with a bypass relay, and what each will and will not do. We would rather lose a sale to a cheaper part than sell you one that does not fit.

Specification

• Fits: any trailer, and any vehicle with a 7 pin or 13 pin socket. A 13 pin to 7 pin adaptor is on the electrics page if your car and your trailer disagree
• Approval: E marked to the UNECE regulations for each lamp function: R7 for position and stop, R6 for direction indicators, R4 for the plate lamp and R38 for the fog. An unmarked lamp is not road legal and the marking is moulded into the lens
• Rating: filament, with replaceable bulbs supplied
• D value: not applicable, this is an accessory rather than a load bearing towing part
• Noseweight: not applicable
• Ball height: not applicable
• Electrics: 7 pin as supplied, wired to the ISO standard and with the pin functions printed on a card
• Fitting time: minutes. A board straps on and plugs in
• Bumper: not applicable
• Materials: the specification we would fit to our own vehicle, with the parts that wear chosen for life rather than for price
• Weight: approximately 0.2 kilograms
• Guarantee: two years
• The law: if the trailer or the load hides the vehicle's own lights or number plate, a board is required, and the plate must match the towing vehicle
• Voltage drop: filament lamps on a seven metre cable can drop enough voltage to dim visibly. If that matters, buy the LED version
• Fog lamp: required on a trailer over 1.3 metres wide, and it must be on the offside or the centre
• Testing: test under load. A test lamp will light on a circuit that cannot run a lamp, and the test box on this page is how you find that out in a driveway rather than on a motorway

What arrives

• the board or lamps
• the cable and plug where included
• bulbs where the lamps are filament
• straps or brackets
• a pin function card

Fitting

Minutes. Strap it on, plug it in, and test every function before you move, including the fog and the plate lamp, which are the two nobody checks and the two an officer will.

Before you order

LED against filament is the only decision worth making here. LED draws a fifth of the current, which on a seven metre cable is the difference between bright lamps and dim ones, and it is sealed so it survives being left outside. Filament is half the price and the bulbs are replaceable, which on a trailer used twice a year is perfectly sensible.