Output Current Test
This test determines whether or not the generator gives the correct output current.PREPARATION
1. Prior to the test, check the following items and correct as necessary.
1. Check the battery installed in the vehicle to ensure that it is in good condition. The battery checking method is described in "BATTERY".
The battery that is used to test the output current should be one that has been partially discharged. With a fully charged battery, the test may not be conducted correctly due to an insufficient load.
2. Check the tension of the generator drive belt. The belt tension check method is described in "COOLING".
2. Turn off the ignition switch.
3. Disconnect the battery ground cable.
4. Disconnect the generator output wire from the generator "B" terminal.
5. Connect a DC ammeter (0 to 100 A) in series between the "B" terminal and the disconnected output wire. Be sure to connect the (-) lead wire of the ammeter to the disconnected output wire.
NOTE: Tighten each connection securely, as a heavy current will flow Do not rely on clips.
6. Connect a voltmeter (0 to 20 V) between the "B" terminal and ground. Connect the (+) lead wire to the generator "B" terminal and the (-) lead wire to a good ground.
7. Attach an engine tachometer and connect the battery ground cable.
8. Leave the engine hood open.
TEST
1. Check to see that the voltmeter reads the same value as the battery voltage. If the voltmeter reads 0 V, there is an open circuit in the wire between the generator "B" terminal and battery (-) terminal. Check for a blown fusible link or poor ground.
2. Start the engine and turn on the headlights.
3. Set the headlights to high beam and the heater blower switch to HIGH. Quickly increase the engine speed to 2,500 rpm and read the maximum output current value indicated by the ammeter.
NOTE: After the engine starts up, the charging current will quickly drop. Therefore, the above operation must be done quickly to read the maximum current value correctly
RESULT
1. The ammeter reading must be higher than the limit value. If it is lower, but the generator output wire is in good condition, remove the generator from the vehicle and test it.
Limit value (95 A generator) : 63 A min.
NOTE
- The nominal output current value is shown on the nameplate affixed to the generator body
- The output current value changes with the electrical load and the temperature of the generator itself. Therefore, the nominal output current may not be obtained. If such is the case, keep the headlights on to discharge the battery.
The nominal output current may not be obtained if the temperature of the generator itself or the ambient temperature is too high.
In such a case, reduce the generator's temperature before testing again.
2. Upon completion of the output current test, lower the engine speed to idle and turn off the ignition switch.
3. Disconnect the battery ground cable.
4. Remove the ammeter, voltmeter and the engine tachometer.
5. Connect the generator output wire to the generator "B" terminal.
6. Connect the battery ground cable.
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 the ignition switch to the OFF position.
3. Disconnect the negative battery cable.
4. Disconnect the generator output wire from the generator "B" terminal. Connect a DC test ammeter with a range of 0 - 100 A in series between the "B" terminal and the disconnected output wire. (Connect the (+) lead of the ammeter to the "B" terminal. Connect the (-) lead of the ammeter to the 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 - 20 V between the generator "B" terminal and the ground. (Connect the (+) lead of the voltmeter to the "B" terminal, and then connect the (-) lead of the voltmeter to the ground.)
6. Connect the negative battery cable.
7. Connect a tachometer or the scan tool.
8. Leave the hood open.
9. Check that the reading on the voltmeter is equal to battery voltage.
NOTE: If the voltage is 0 V, the cause is probably an open circuit in the wire or fusible link between the generator "B" terminal and the battery (+) terminal.
10. Start the engine, and turn the headlights on.
11. Switch the headlights to high beam, turn the heater blower switch to high, increase the engine speed to approx. 2,500 rpm, and read the maximum current output displayed on the ammeter.
Limit: 70% of nominal output current
NOTE
- For the nominal current output, refer to the Generator Specifications.
- Because the current from the battery will drop soon after the 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 the electrical load and the 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 the headlights on with the engine off to discharge the 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 the generator to cool before testing.
12. The reading on the ammeter should be above the limit value. If the reading is below the limit value and the generator output wire is OK, remove the generator from the engine and check the generator.
13. Run the engine at idle speed after the test.
14. Turn the ignition switch to the OFF position.
15. Disconnect the tachometer or the scan tool.
16. Disconnect the negative battery cable.
17. Disconnect the ammeter and voltmeter.
18. Connect the generator output wire to the generator "B" terminal.
19. Connect the negative battery cable.