Troubleshooting Boat Trailer Lights. I have noticed people disconnecting their trailer lights when launching, Is this really necessary? Your trailer's lights are essential to safe operation.
Replacing the whole system is cheaper and better for your blood pressure. Trailers Lights, Reflectors and Trailer Wiring. However, on (boat) trailers, many people are having trouble with individual LEDs going "out".
Are your boat trailer lights not working when you turn them on?
Even small trailers like this one for towing motorcycles need to be wired to your vehicle.
If you are troubleshooting a trailer, do not connect the trailer hitch to the tow vehicle ball and do not connect the safety chains or cables. Launching and recovering using a boat trailer can be a stressful experience. I too checked the fuses that were good in the cab & under the hood.