trailer wire roll | eBay Find great deals on eBay for trailer wire roll. Shop with confidence. Skip to main content. eBay Logo: Primary Trailer Light Cable Wiring Harness 16 Gauge 100' Wire Roll Black Camper See more like this. Primary Trailer Light Cable Wiring Harness 16 Gauge 100' Wire Roll White Camper. Trailer Wire - Agri Supply Find the best trailer wire for horse trailers, hay trailers and boat trailers. We have trailer light wiring for whatever you might be pulling behind your tractor, SUV or rig. Get the right trailer wire from Agri Supply to hook up tail lights, turn lights, interior lights, warning lights and any other electrical trailer parts.