Which statement best describes what an electrical wiring diagram shows?

• A. Battery voltage ratings and fuse types
• B. Troubleshooting steps for each circuit
• C. The sequence of maintenance procedures
• D. Circuit connections, wire colors, locations, and components

Answer: (D)

An electrical wiring diagram shows how circuits are physically wired in the aircraft: which wires connect to which components, the colors of the wires, where each wire runs, and the locations of connectors and devices. This lets you trace a circuit from the power source through switches, relays, and loads, and find the exact harness routes and terminations during installation or repair. It’s about the actual wiring layout, not the circuit’s function or maintenance steps. Voltage ratings and fuse types appear in component specs or electrical load diagrams, while troubleshooting procedures belong in the troubleshooting guides.