Curt Manufacturing's # 55384 GMC Sierra 3500 Trailer Wiring Kit T-Connector Harnesses are designed to make connecting your trailers wiring a snap. No need to cut or modify your vehicles existing wiring harness, Curt's custom fit T-connector trailer wiring kits will plug right into your existings factory wiring. On most vehicles this simple design only requires you to unplug your stock harness at its connection point (usually located near your taillights) and then plug in the new Curt GMC Sierra 3500 wiring kit. This requires no cutting or no soldering of any of the wires. Built-in converters are pre-wired into applications that require taillight conversion. Once installed this Curt 55384 kit will provide a standard 4 wire flat connection you connect you GMC Sierra 3500 to your trailer.