In order to find a parts diagram, use the content page and locate the section where it is listed. Service manuals are organized by several chapters, each one highlighting a specific part of the vehicle. Electrical components, for example, are found in the chapter dedicated to electrical components.
Although the sections vary according to the type of vehicle, a manual is generally separated into the powertrain, drivetrain, exterior, interior and electrical chapters. Each chapter will also have sub-sections, which will break it up and organize the components of the vehicle. Locate the section that displays the system for the part, and browse through the chapter to find the diagram.