SEMI TRAILER WIRING CODE

Wiring Diagram for a 1997 Peterbilt Semi Tractor with 7
Wiring Diagram for a 1997 Peterbilt Semi Tractor with 7-Pin Round Connector The wiring color codes and wire gauge recommendations for the Pollak Heavy-Duty, 7-Pole, Round Pin, Trailer Wiring Connector, item # PK11700, are listed below. White - Ground Return - 8 gauge Black - Clearance, Side Marker, Identification - 12 gauge
Troubleshoot Trailer Wiring by Color Code - ThoughtCo
Jul 15, 2018Whether you're installing a new trailer light circuit in your car or truck or trying to troubleshoot trailer wiring that is not working, you'll need to understand what each wire in the trailer wiring harness does, where it likely goes, and why it may not be working well.