Motor Trike Trailer Hitch Wiring Harness For Harley Tri-Glide This wire harness is essential for hooking up a Harley-specific (4 wire) trailer and it maintains the integrity of the original Trike wire harness. Features: Connector allows for auxiliary power to be run to trailer Wiring is plug-and-play with no splicing required Made in the USA Note: Compatible with Harley-specific (4 wire) trailers only.