This manual provides comprehensive wiring diagram schematics for the family, covering models 357, 375, 377, 378, and 379 produced from July 1994 through 2008. Trucks are renowned for their robust construction, customizable configurations, and suitability for demanding vocational and long-haul applications. This specific series, including the iconic 379, represents a significant lineage of heavy-duty trucks, often equipped with powerful Cummins or Caterpillar engines and reliable Eaton transmissions, designed for exceptional performance and durability.

This wiring diagram schematic manual is an essential resource for diagnosing and repairing the complex electrical systems found in these trucks. It meticulously details all vehicle electrical circuits, including lighting, instrumentation, powertrain management, HVAC, and chassis systems. The manual includes troubleshooting guides, component identification, fuse and relay locations, ground point identification, and connector pinouts, all presented with high-resolution diagrams and clear explanations of wire color codes and circuit logic. Its advanced technical depth makes it invaluable for professional technicians, fleet maintenance personnel, and experienced owners seeking to maintain the operational integrity and safety of their vehicles.

This manual provides comprehensive wiring diagram schematics for the family, covering models 357, 375, 377, 378, and 379 produced from July 1994 through 2008. Trucks are renowned for their robust construction, customizable configurations, and suitability for demanding vocational and long-haul applications. This specific series, including the iconic 379, represents a significant lineage of heavy-duty trucks, often equipped with powerful Cummins or Caterpillar engines and reliable Eaton transmissions, designed for exceptional performance and durability.

This wiring diagram schematic manual is an essential resource for diagnosing and repairing the complex electrical systems found in these trucks. It meticulously details all vehicle electrical circuits, including lighting, instrumentation, powertrain management, HVAC, and chassis systems. The manual includes troubleshooting guides, component identification, fuse and relay locations, ground point identification, and connector pinouts, all presented with high-resolution diagrams and clear explanations of wire color codes and circuit logic. Its advanced technical depth makes it invaluable for professional technicians, fleet maintenance personnel, and experienced owners seeking to maintain the operational integrity and safety of their vehicles.