Electrical Wiring Diagrams to Service Agricultural and Off-Highway Equipment: A Systematic Approach

This paper reviews the development of an electrical diagnostic presentation adopted for John Deere products worldwide. Deere has adopted IEC 617 electrical symbols and incorporated them into a standard presentation format to simplify and improve the communication of electrical information to dealer technicians who service John Deere equipment.

The diagnostic presentation is designed to provide the end user, the service technician, a common method for diagnosing electrical problems. It utilizes a combination of diagrams prepared by product engineering and service groups. Engineering is responsible 1) for developing a functional schematic diagram to explain the operation, function and interaction of the electrical devices, and 2) for developing a wiring diagram to show the harness flattened out with connectors and devices. Service is responsible 1) for developing a component location drawing showing the profile of the equipment and dimensional relationship between devices, and 2) for developing specific diagnostic schematics to aid in specific diagnosis instructions. All diagrams are interconnected through use of consistent labeling and identification legends between drawings.

In addition to a standardized identification code for each device, the diagram is made easier to read by adding an international symbol to help explain the function of devices and nomenclature.