This manual pertains to the 379, a distinguished heavy-duty truck model produced from 1987 to 2007. Known for its classic styling, robust construction, and a high degree of customization, the Model 379 served as a flagship in the lineup, catering to long-haul, vocational, and specialized applications. It was engineered with a legacy of quality and reliability, offering a comfortable and durable platform for demanding work. This particular guide focuses on the comprehensive electrical systems that underpin the functionality and performance of all 379 Model Family variants, ensuring these powerful machines operate at peak efficiency.

The purpose of this Electrical Schematic Manual is to provide detailed technical information for the diagnosis, maintenance, and repair of the 379's electrical systems. It covers a wide array of components and circuits, including powertrain, chassis, cab, and exterior electrical functions, as well as instrumentation and lighting controls. Within its approximately 400-600 pages, users will find essential wiring diagrams, component locations, fuse and relay assignments, diagnostic flowcharts, and specific procedures for troubleshooting, component testing, and connector repair. This resource is designed for fleet maintenance managers, owner-operators, and technicians, offering factory-level detail to efficiently resolve electrical issues and maintain the operational integrity of the vehicle.