What Are the Proper Wiring Connections for an Alternator?

Alternators typically use four wires which connect the ground, output, sensor and ignition indicator. These are known as the L, IG, S, B and F terminals. Alternators are ground either through their outer casing or a separate wire terminal connected to either the engine block or chassis. The output wire transfers current to the battery and is typically brown in color. The sensor terminal monitors voltage output, and the indicator receives voltage from the ignition switch.