As graphically illustrated in the 3-wire alternator wiring diagram, the main wirings include the exciter wire positive & negative cables. It should be noted here that the exciter wire is connected to the L-terminal of an alternator and is widely used to turn on the voltage regulator. In the following wiring diagram, several electrical components are aligned together. Components like Battery, Starter Motor, Ballast Resistor, Ignition Switch, Ignition Light, Lighting Switch, Lucas 7FJFuse Box, Lucas 15 ACR Alternator, and more have their respective purposes. As you can see, the S-terminal senses battery voltage, the IG terminal is the ignition switch that turns the voltage regulator on, the L-terminal closes the circuit to the warning lamp, and more.
