Boat Trailer Wiring Harness | etrailer and includes a wiring harness for easy installation. Polyester strap and snap hook included Wiring harness included 25' Positive battery wire and 8' ground wire Removable plastic plug for emergency handle use Accepts 5/8" deep socket Requires. Electric Winch. Boat Trailer Winch. Utility Winch. Polyester Strap. Standard Duty. Dutton-Lainson. No Boat Trailer Wiring Harnesses | iBoats Boat Trailer Wiring Harnesses - Since 1998, iboats is the most trusted water lifestyle online store for boat parts and accessories, boats for sale, and forums. Enjoy great priced products with fast shipping.