Output Current Test

Required special tool: MB991502: Scan Tool (MUT-II). This test determines whether the generator outputs normal current. See Fig 1 .

Fig 1: Output Current Test

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

1. This test, always be sure to check the following:
   • Generator installation.
   • Battery.
     NOTE: Battery to be used should be slightly discharged. The load in a fully-charged battery will be insufficient and test may not be able to be carried out correctly.
   • Generator drive belt tension.
   • Fusible link.
   • Abnormal noise from the generator while the engine is running.
2. Turn ignition switch to LOCK (OFF) position.
WARNING: Battery posts, terminal and related accessories contain lead and lead compounds. Wash hands after handling.
WARNING: Never use clips to connect line. Loose connections (e.g. using clips) will lead to a serious accident because of high current.
3. Disconnect negative battery cable.
NOTE: A clamp-type ammeter which enables measurements to be take without disconnecting generator output wire is recommended.
4. Disconnect generator output wire from generator B terminal and connect a DC test ammeter with a range of 0-100A in series between B terminal and disconnected output wire. (Connect positive lead of ammeter to B terminal and then connect negative lead o ammeter to disconnected output wire.)
5. Connect a voltmeter with a range of 0-20V between generator B terminal and ground. (Connect positive lead of voltmeter to B terminal and then connect negative lead of voltmeter to ground.)
6. Connect negative battery cable.
7. Connect a tachometer or scan tool MB991502.
8. Leave hood open.
NOTE: If voltage is 0V, cause is probably an open circuit in wire of fusible link between generator B terminal and battery positive terminal.
9. Check to be sure that the reading on voltmeter is equal to battery positive voltage.
NOTE: Because current from battery will soon drop after engine is started, the next step should be carried out as quickly as possible in order to obtain maximum current output value.
10. After turning light switch ON and turning on headlights, start engine.
NOTE: The current output value will depend on electrical load and temperature of generator body.
If electrical load is small while testing, specified level of current may not be output even though generator is normal. In such cases, increase electrical load by leaving headlights turned ON for some time to discharge battery or by using lighting system in another vehicle and then test again.
The specified level of current also may not be output if the temperature of the generator body or ambient temperature is too high. In such cases, cool generator and then test again.
11. Immediately after setting headlights to high beam and turning heater blower switch to high revolution position, increase engine speed to 2,500 RPM and read maximum current output value displayed on ammeter. Limit value: 70% of nominal current output.
12. Reading on ammeter should be above limit value. If reading is below limit value and generator output wire is normal, remove generator from engine and check generator.
13. Run engine at idle speed after test.
14. Turn ignition switch to LOCK (OFF) position.
15. Disconnect tachometer or scan tool MB991502.
16. Disconnect negative battery cable.
17. Disconnect ammeter and voltmeter and tachometer.
18. Connect generator output wire to generator B terminal.
19. Connect negative battery cable.