Alternator Output Test

NOTE: During alternator output test, a slightly discharged battery should be used as a fully charged battery may not allow full alternator output.

Turn ignition switch to OFF position. Disconnect negative battery cable. Disconnect alternator output wire from terminal "B". Install positive lead of 100-amp ammeter to terminal "B" and negative lead to disconnected output lead.
CAUTION: Tighten each connection securely as heavy current flow will exist. DO NOT use clips on ammeter.
Connect positive voltmeter lead (0-20 volts) to alternator terminal "B" and negative lead to ground. Install tachometer, and reconnect negative battery cable.
Ensure voltmeter indicates battery voltage. If no voltage exists, an open circuit is present in wire between alternator terminal "B" and negative battery terminal. Check grounds and fusible link.
Turn headlights on, and start engine. Set headlights at high beam and heater switch on HIGH. Quickly accelerate engine speed to 2500 RPM and note alternator output current on ammeter. Minimum output should be within specification. See ALTERNATOR MINIMUM OUTPUT SPECIFICATIONS table.
NOTE: Output voltage changes with electrical load and temperature. Ensure proper electrical load is applied while checking output. Nominal output may not be obtained if alternator or ambient temperature is excessive. Allow alternator or temperature to cool, and recheck output. Alternator output is stamped on metal plate attached to alternator case.
If minimum output is not obtained and alternator wiring is okay, repair alternator. Disconnect negative battery cable, and remove test equipment.

ALTERNATOR MINIMUM OUTPUT SPECIFICATIONS

Application	Amps
Non-Turbo	45.5
Turbo	52.5