7 Pin Trailer Wiring Harness | etrailer Install a 7-way, RV-style trailer connector on your vehicle with this easy-to-splice harnessLite draws power directly from the battery to avoid overloading your vehicle's circuits. Brake electrical system Includes harness with 4-pin connection point for plugging in a brake controller wiring adapter (sold separately) Supplies required fuses, wire taps, and additional hardware Constructed Amazon: trailer wiring harness 7 way wwwon›Search›trailer wiring harness 7 wayPrimelux 10ft 7-way Trailer Cord with Junction Box - 7-Pin Trailer Connector Plug Wiring Harness - 7 Blade Copper Wire Cable for RVs, Campers, Trailers, Towing Vehicles (10ft with Junction Box) 4.0 out of 5 stars 1. $39 $ 39. 95. Get it as soon as Tomorrow, Apr 9. FREE Shipping by Amazon.