4 Wire Trailer Wiring. If the trailer plug wiring on your vehicle or trailer is damaged or not working correctly, you can replace the connector with a CURT splice-in plug or socket. Learn how to repair a trailer wiring harness that was damaged when borrowed by someone who did not connect the wiring to their vehicle.
We recommend these standards because they are pretty universal. When buying wires for trailers, make sure they are the right thickness to increase durability. In fact, most vehicles, especially those meant for towing, come prewired and ready to roll.
That said, for specific situations, there are industrial standards with different connectors and wire arrangements.
Trailer Wiring Diagrams showing you the typical wiring for most single axle trailer and tandem axle trailers.
Find the trailer light wiring diagram below that corresponds to your existing configuration. Very tough cable with resistance to cracking, abrasion, oil, grease, acid, and weather. When buying wires for trailers, make sure they are the right thickness to increase durability.