The three wire types in a three-wire alternator include the battery positive wire, the voltage sensing wire, and the ignition input wire. The battery positive wire connects to the starter. The voltage sensing wire connects to the battery, and the ignition wire connects from the alternator to the key switch.

What does IG mean on an alternator?

IG terminal - Ignition switch that turns the voltage regulator on. L terminal - Closes the circuit to the warning lamp. B terminal - Main alternator output terminal (connected to the battery)

What does l and s mean on an alternator?

S terminal - Senses battery voltage. L terminal - Closes the circuit to the warning lamp. B terminal - Main alternator output terminal (connected to the battery) F terminal - Full-field bypass for regulator.