What is the purpose of a wiring diagram in bus troubleshooting?

• A. It shows connections, component locations, and test points to trace circuits and verify wiring against the actual vehicle.
• B. It lists daily maintenance tasks for the electrical system.
• C. It shows only the color codes used for wires.
• D. It tells you the order to remove panels on the vehicle.

Answer: (A)

Wiring diagrams map how the electrical system is laid out, showing how circuits are connected, where components sit, and where to find test points. This lets you trace a circuit from the power source through switches, relays, fuses, and loads, so you can verify the actual wiring on the bus matches the intended design and pinpoint where a fault may be. Daily maintenance tasks aren’t shown in wiring diagrams, color codes alone don’t reveal full circuit paths or locations, and the diagram doesn’t specify a panel-removal sequence, so it wouldn’t help with systematic troubleshooting.