Information about Trailer Lighting

A trailer’s electrical system consists of a connector, wiring, and lamps. The connector plugs into the rear of the towing vehicle, supplying power to the trailer so that all lights function correctly. Making sure your trailer lighting is complete, correctly fitted, and in good working order is a legal requirement in most countries — and essential for road safety. Use our lighting diagram tool to find the right parts for your trailer’s electrical system.

Trailer Lighting Functions

A complete trailer lighting system includes several different lamps, each serving a specific purpose. The trailer connector (available in 7-way and 13-way variants) connects to the car and powers all the lights. Position lights at the front of the trailer emit a white light. Side marking lights emit an orange light and make the trailer visible from the side. At the rear, tail lights emit a red light and also incorporate indicators, brake lights, and a reflector. Number plate lights illuminate the rear registration plate. Depending on the trailer, reverse lights may also be included. Reflectors are required at the rear and sides to ensure visibility in low light conditions.

What Type of Lamp Should I Choose?

If one of your tail lights has failed, you need to replace it with a lamp that matches the opposite side — trailers must have symmetrical lighting. You can switch to a different model, but if you do, you must replace both the left and right tail lights at the same time to maintain symmetry. Browse tail lights to find a matching replacement for your trailer.

Position Lights and Number Plate Lights

Position lights are mounted at the front of the trailer and must emit a white light. They indicate the width of the trailer to other road users. Number plate lights illuminate the rear registration plate and are a legal requirement. Both should be checked regularly and replaced if damaged or failing.

Advantages of LED Lighting

LED lighting offers a number of advantages over traditional bulb-based lamps. LED lamps last significantly longer and require no bulb replacements. They are typically waterproof, provide a brighter and clearer light output, and have a more modern appearance. Valeryd stocks a wide range of LED lighting for trailers and caravans.

Lighting Kits

A lighting kit is a complete package solution that includes everything needed to wire a trailer from scratch: a trailer connector, cables, tail lights, side marking lights, and width marking lights, along with clips and installation tools. Lighting kits are ideal when building a new trailer or doing a full lighting replacement. See our range of electrical plugs and electrical sockets for connectors and cabling.

(1) Trailer connector
The trailer connector is connected to the car. There are two variants, one 7-way and one 13-way.

(2) Position lights
The position lights illuminate with a white light, and are located on the front of the trailer.

(3) Side marking lights
The side marking lights illuminate with an orange light.

(4) Tail lights
The tail lights are located at the very rear and illuminate with a red light. In addition to the tail lights, there are also indicators, brake lights and a reflector. Depending on the model, there can also be fog lights, number plate lighting and reversing lights.