Toyota Tacoma Trailer Wiring | etrailer Trailer Wiring Harness Installation - 2013 Toyota Tacoma. Today on our 2013 Toyota Tacoma we'll be having a look at and installing the Tekonsha T1 Vehicle Wiring Harness with Four Pole Flat Trailer Connector, part number 118496. 2019 Toyota Tacoma Hitch Wiring | Harnesses, Adapters wwwd››Trailer Hitches›Hitch Wiring›Toyota›TacomaToyota Tacoma 2019, Towing Wiring Harness by Tekonsha®. One-year warranty. Wire up your tow vehicle and trailer with whatever it takes to get your trailer lights on, the electric brakes slowing down, and the trailer battery charging..