Lighting and electrics on trailers: what is mandatory and what is better to have?
Good lighting and a reliable electrical connection should not be accessories; it is pure safety. A properly lit trailer not only prevents fines, but also accidents. In this article, we explain which lights are mandatory, which extras are smart, and what to watch out for when it comes to your trailer’s electrics. We also refer to the Hapert wiring diagram so you always know how the wiring is supposed to go.
What is legally required lighting?
For starters, any trailer going on the road must have properly working lights. The law requires every trailer to have red tail lights, brake lights, turn signals and license plate lights. A rear fog light is mandatory for smaller trailers up to 750 pounds, and the same is true for heavier trailers if they entered the road after 1998.
Trailer dimensions also play a role. A model wider than 1.60 meters must have front city lights. If the trailer is wider than 2.10 meters or longer than 6 meters, marker lights are mandatory. All lighting must be securely fastened, remain highly visible and technically sound. So loose cables, dull bulb glasses or half-working bulbs are not an option; that’s asking for trouble.
Extras that make a difference
At Hapert, we already provide more than what is required by law as standard. Not because we have to, but because we believe that reliability starts there. Still, there are a few choices that give you, the user, extra comfort and security.
For example, more and more people are choosing LED lighting. Those bulbs are more energy efficient, more resistant to vibration and last much longer than traditional incandescent bulbs. In addition, connection is crucial. A sturdy 13-pin plug prevents interference and ensures a stable connection to the car. Many lighting problems arise from poorly connected or rusty plugs, so a proper connection pays for itself quickly.
(The type of wiring and ground connection also play a role. A properly laid wiring harness protects against water and wear and tear which prevents malfunctions on the road. A poor ground connection is often the cause of blinking or non-working lights. And finally: a quick check before departure works wonders. A quick check that all lights are on and the plug is securely fastened takes hardly any time, but prevents a lot of hassle on the road).
The wiring diagram
For lighting to work properly, it is helpful to know how the wiring runs. The Hapert connection diagram shows exactly which pin in the plug is intended for which function. This prevents accidental voltage being applied to the wrong wire.
https://hapert.com/wp-content/uploads/2023/12/Aansluitschema.pdf
Modern trailers almost always use a 13-pin connection, as it supports more features than the older 7-pin version. It is important to follow the colors of the wires correctly and make sure that the ground connection is tight. A loose contact or some moisture in the plug can be enough to cause the lights to blink or fail. Therefore, regularly check the wiring harness for wear or damage, and after each adjustment, test that all lights work properly.
Why quality in lighting pays off
At Hapert, we believe that quality is in every detail; from the steel construction to the smallest cable in the electrical system. Solid lighting and electrics mean fewer breakdowns, less maintenance and, most importantly, more peace of mind. Those who choose sturdy components, waterproof connections and durable materials will save time and money in the long run.
In addition, a well-maintained trailer exudes professionalism. A brightly lit taillight or a sleek LED strip makes just that difference in appearance, especially for businesses whose trailers are on the road daily. And should you ever want to sell your trailer, a flawless electrical system is always a plus.
The Hapert pre-departure checklist
Before you hit the road, run through these points:
- Do all rear and brake lights work on the left and right?
- Are the turn signals flashing as they should?
- Is the license plate light on?
- Does the rear fog light work when needed?
- Are marker lights present and intact on wide trailers?
- Is the plug firmly attached and the cable undamaged?
- Has the ground connection been checked?
A short check, but a big difference in safety!
Ask a dealer for advice
Our dealers have years of experience with our products. Should something not work, they are there to help you. They can provide you with an adapter, check the wiring and repair it if necessary. With our dealers, you are always in good hands. Find a dealer near you below to make your trailer safe and visible again.