Some KENWORTH Truck Service Manuals PDF & Wiring Diagram above the page. Kenworth is an American company that is part of a well-known group of Paccar companies (Service Manuals PDF page), specializing in the production of truck tractors, as well as heavy trucks. The products of this company are characterized by the highest quality of assembly, as well as excellent performance characteristics.. 2. repair manuals & instructions 3. wiring diagrams 4. hardware and software for diagnostics. Our founder, Harky Runnings, incorporated Red Dot in 1965 to develop heating and air conditioning. products specifically for heavy-duty vehicles and off-highway equipment..