This document provides detailed wiring diagrams for the Hitachi Zaxis 450, 500, and 520 excavators. It includes comprehensive schematics that illustrate the electrical connections, wiring routes, and component locations for key systems such as the engine, hydraulic controls, lighting, sensors, and operator controls. The diagrams are essential for diagnosing and troubleshooting electrical issues, helping technicians identify circuit pathways and connections. This resource is crucial for ensuring accurate repairs and maintenance of the electrical systems, contributing to the reliable operation of the excavators.