Your trailer’s lights are only as good as its wiring.
Keeping your trailer’s running lights in perfect order is essential for your safety and legally required to let other drivers know your intentions. If your trailer’s lights are on the fritz, the problem can often be traced to the wiring. Boat trailer light wiring consists of a plug connected to the tow vehicle’s lighting circuitry, a matching trailer light connector on the trailer wiring harness, a wiring harness that runs the length of the trailer frame and a variety of lights around the trailer’s perimeter. When selecting a trailer wiring kit, be sure to choose one that is compatible with your vehicle’s lighting wires. To help you with making the connections to your vehicle, trailer wiring harnesses have color coded wires. Varieties of trailer wire connectors include 2-, 3-, 4 and 5-pole flat connectors. These are also referred to as “2-, 3-, 4- or 5-way connectors”. Round connectors are also available.
Related: Step-by-step guide for replacing trailer lights and wiring harness.