Harness Connectors - Walmart Harness Connectors. Auto & Tires. Automotive Tools & Equipment. Automotive Electrical. Harness Connectors. Product - 25' Camper RV Truck Trailer 7 Way Flat Pin Wiring Harness / Round Plug Connector. Product Image. Price $ 59. 99. Product Title. 25' Camper RV Truck Trailer 7 Way Flat Pin Wiring Harness / Round Plug Connector. Wiring Harnesses, Plugs, and Accessories - Agri Supply Trailer wire connectors at Agri Supply are marked for the makes, models and years of vehicles so you can find a perfect fit. Trailer wiring kits include everything you need to hook up your vehicle to a trailer, whether you are driving a Dodge, a Toyota or a GMC.