Amazon: 7 way wiring harness 7 Way Trailer Cord, Kohree Heavy Duty 7 Way Trailer Plug Inline Cord Wire Harness Cable Double Prongs Connector 8 Feet for Truck Camper Blade Molded RV Cable Wire, Weatherproof Anti-corrosive. 4.4 out of 5 stars 63. $22 $ 22. 99. Get it as soon as Tue, Oct 15. 7 Way Wiring Harness | etrailer Reese Multi-Plug Wiring Harness for Factory Tow Package - 7-Way and 4-Way Flat Trailer Connectors. Quickly and easily install this custom harness to get a 7-way and a 4- way trailer connector on your vehicle. Connector plugs into OEM tow package wiring harness - no cutting or splicing required.