Generator Output Current Test

This test determines if the generator output current is normal.

1. Before testing, be sure to check the following:
   • Generator installation and wiring connections.
   • Battery.
   • Generator drive belt tension.
   • Fusible link.
   • Abnormal noise from the generator while the engine is running.
   NOTE: The battery used should be slightly discharged. The load needed by a fully-charged battery is insufficient for an accurate test.
2. Turn ignition switch to OFF position.
3. Disconnect negative battery cable.
4. Disconnect generator output wire from generator "B" terminal. Connect a DC test ammeter with a range of 0-100A in series between "B" terminal and disconnected output wire. Connect (+) lead of ammeter to "B" terminal. Connect (-) lead of ammeter to disconnected output wire.
   CAUTION: Never use clips. Use bolts and nuts to connect the line. Otherwise, loose connections (e.g. using clips) may lead to a serious accident because of high current.
   NOTE: An inductive-type ammeter which enables measurements to be taken without disconnecting the generator output wire is recommended.
5. Connect a voltmeter with a range of 0-20V between generator "B" terminal and ground. Connect (+) lead of voltmeter to "B" terminal, then connect (-) lead of voltmeter to ground.
6. Connect negative battery cable.
7. Connect a tachometer or scan tool.
8. Leave the hood open.
9. Check that the reading on voltmeter is equal to battery voltage.
   NOTE: If the voltage is 0V, the cause is probably an open circuit in wire or fusible link between generator "B" terminal and battery (+) terminal.
10. Start engine and turn headlights ON.
11. Switch headlights to high beam, turn heater blower switch to high, increase engine speed to approximately 2500 RPM, and read maximum current output display on ammeter. See GENERATOR OUTPUT SPECIFICATIONS  table.
    NOTE:

    For nominal current output, see GENERATOR OUTPUT SPECIFICATIONS  table.

    Because the current from battery will drop soon after engine is started, steps  10 and 11  should be carried out as quickly as possible in order to obtain the maximum current output value.

    The current output value will depend on electrical load and temperature of the generator body.

    If insufficient electrical load is used while testing, the specified level of current may not be output , even though the generator is normal. In such a case, increase the electrical load by leaving headlights on with engine off to discharge battery before testing.

    The specified level of current may not be output if the temperature of the generator body and/or ambient temperature is too high. In such a case, allow generator to cool before testing.

12. The reading on the ammeter should be above the limit value. If the reading is below limit value and generator output wire is okay, remove generator from engine and check generator.
13. Run engine at idle speed after test.
14. Turn ignition switch to OFF position.
15. Disconnect tachometer or scan tool.
16. Disconnect negative battery cable.
17. Disconnect ammeter and voltmeter.
18. Connect generator output wire to generator "B" terminal.
19. Connect negative battery cable.