2005 Chevrolet Silverado Trailer Wiring | etrailer Call 800-298-8924 to get Expert Service ordering a Trailer Wiring for your 2005 Chevrolet Silverado. Complete installation instructions and lifetime technical support on all Trailer Wiring purchases. 2005 Chevrolet Silverado Trailer Wiring. Select Vehicle Style: Wiring For 7-Way Connector on 2004 Chevrolet Silverado Vehicle manufacturers have intermittently changed wiring colors over the years. The Pollak 7 and 4 Way Trailer Connector Socket, part # HM40975 , you have referenced is designed to plug into a round factory connector that is usually located above the spare tire on a 2004 Silverado.