4 Plug Wire Harness | etrailer Quickly and easily install a 4-way and 7-way trailer connector on your vehicle with this custom harness.T-connector plugs directly into OEM tow package wiring harness - no cutting or splicing vehicle's factory tow package wiring harness, which is located at the rear of your vehicle, slightly toward the driver's side installation is complete, the connectors will be stowed beneath your Amazon: 4 wire trailer harness Miady 25ft Trailer Wiring Harness with 4 Flat Connector, 18 AWG Color Coded Wires Trailer Light Wiring Harness Extension with 4ft White Ground Wire. 4.7 out of 5 stars 8. $12 $ 12. 99. Get it as soon as Tue, Sep 10. FREE Shipping on orders over $25 shipped by Amazon.