This manual pertains to the FM / FH Series Trucks, a robust line of heavy-duty commercial vehicles renowned for their engineering quality, driver comfort, and advanced safety features. These trucks are designed for long-haul and regional transport, featuring powerful D13 Series engines, available in configurations from 380 hp to 550 hp, and commonly equipped with the innovative I-Shift automated manual transmission. With a legacy of reliability and innovation, trucks are a leading choice in the competitive heavy-duty market, known for their fuel efficiency and comprehensive safety systems, including adaptive cruise control and lane keeping support.

This Electrical Wiring Diagram Manual provides comprehensive coverage of the complex electrical systems within the FM and FH Series trucks, specifically detailing wiring for D13A, D13B, and D13C engines and supporting EU3, EU4, and EU5 emission standards. It includes detailed schematics for all vehicle electrical systems, engine management, powertrain control, chassis systems, and body electronics. The manual is an essential resource for technicians and mechanics, offering clear diagrams, component identification, fuse and relay information, ground point locations, and troubleshooting guides to facilitate accurate diagnosis and repair of electrical faults, ensuring optimal vehicle performance and longevity.