Schematic Diagram is a diagram which shows by means of graphic symbols, the electrical connections and functions of a specific circuit arrangement. The schematic diagram is used to trace the circuit and its functions without regard to the actual physical size, shape, or location of the component devices or parts.
Schematic diagram can be used to determine where the trouble might be in the circuit when a malfunction occurs. The schematic diagram does not show the terminals, connector points, and so forth, of the circuit. Therefore, you must go to the wiring diagram to determine where to make the voltage or resistance checks in the circuit when troubleshooting.
Example of Schematic Diagram:
The above picture shows schematic diagram of Honda CB125’s electrical system which consists of A.C. generator, lighting switch, selenium rectifier, voltage meter, ammeter, battery, ignition coil, spark plug, condenser, contact breaker, headlight high beam, headlight low beam, dimmer switch, highbeam pilot light, tail/stop light, meter light.