Generator Output Test

NOTE: A slightly discharged battery should be used, as a fully charged battery may not allow full generator output.

Turn ignition off. Disconnect negative battery cable. Disconnect generator output wire from terminal "B". Connect 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. An inductive-type ammeter is recommended.
Connect positive voltmeter lead (0-20 volts) to generator terminal "B" and negative lead to ground. Install a tachometer and reconnect negative battery cable.
Ensure voltmeter indicates battery voltage. If voltage is not present, check for open circuit in wire between generator terminal "B" and positive battery terminal. Check grounds and fusible link.
Start engine and turn headlights on. Set headlights at high beam and heater blower switch on HIGH. Increase engine speed to 2500 RPM and note generator output current on ammeter. Minimum output should be within specification. See GENERATOR 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 generator or ambient temperature is excessive. Allow generator or temperature to cool, and recheck output. Generator output is stamped on metal plate attached to generator case.
If minimum output is not obtained and generator wiring is okay, repair generator. Operate engine at idle speed after the test.

GENERATOR MINIMUM OUTPUT SPECIFICATIONS