Reese Elite Series Pre-Assembled 5th Wheel Hitch w/ Slider, Wiring ... Reese Elite Series Pre-Assembled 5th Wheel Hitch w/ Slider, Wiring Harness - Single Jaw - 18,000 lbs Reese Fifth Wheel RP30144Reese Trailer Wiring Harness - Buy Reese Towpower 78058 Trailer Wiring Kit: Wiring - Amazon.com FREE DELIVERY possible on eligible purchases. Great for re-doing a simple trailer wiring harness. Only PITA for me was separating the individual wires. There is a very thick secondary shielding applied over the standard wire shield to prevent abrasion from shorting out the wires and just made it that much more difficult to splice.. So, you’ve got your trailer connected to your truck with the right hitch, ball mount and trailer ball. You’re ready to go, but what about your trailer lights?If the trailer connector doesn’t match the one on your tow vehicle, or if the vehicle doesn’t even have a plug, stick around..