This manual pertains to FH and FM Series Trucks equipped with the D13 engine. These heavy-duty commercial vehicles are engineered for long-haul trucking and vocational applications, renowned for their robust construction, advanced safety features, and efficient performance. The D13 engine, a powerful inline 6-cylinder diesel, offers various configurations and power outputs, delivering reliable performance across diverse operational demands. Trucks, with a legacy dating back to 1928, consistently prioritizes safety, quality, and innovation, making the FH and FM series exemplars of modern trucking technology and driver comfort.

This Service Information Manual, specifically focusing on electrical systems, provides comprehensive guidance for FH/FM Series Trucks with D13 engines. Its scope includes the precise location and identification of electronic components, detailed wiring diagrams, harness routing, and module locations. The manual covers a wide array of electrical systems, from engine and transmission control to ABS, BCM, infotainment, and diagnostics. It offers systematic troubleshooting procedures, component testing instructions, and fuse/relay identification, making it an invaluable resource for truck maintenance technicians, fleet managers, and heavy-duty repair shops seeking to maintain and repair these complex vehicles efficiently.

This manual pertains to FH and FM Series Trucks equipped with the D13 engine. These heavy-duty commercial vehicles are engineered for long-haul trucking and vocational applications, renowned for their robust construction, advanced safety features, and efficient performance. The D13 engine, a powerful inline 6-cylinder diesel, offers various configurations and power outputs, delivering reliable performance across diverse operational demands. Trucks, with a legacy dating back to 1928, consistently prioritizes safety, quality, and innovation, making the FH and FM series exemplars of modern trucking technology and driver comfort.

This Service Information Manual, specifically focusing on electrical systems, provides comprehensive guidance for FH/FM Series Trucks with D13 engines. Its scope includes the precise location and identification of electronic components, detailed wiring diagrams, harness routing, and module locations. The manual covers a wide array of electrical systems, from engine and transmission control to ABS, BCM, infotainment, and diagnostics. It offers systematic troubleshooting procedures, component testing instructions, and fuse/relay identification, making it an invaluable resource for truck maintenance technicians, fleet managers, and heavy-duty repair shops seeking to maintain and repair these complex vehicles efficiently.