Mitsubishi MOTORS Space Runner 1999 Workshop Manual Supplement page 610

This test determines whether the voltage regulator
is correctly controlling the alternator output voltage.
1. Always be sure to check the following before
the test.
Alternator installation
Check that the battery installed in the vehicle
is fully charged.
Alternator drive belt tension
Fusible link
Abnormal noise from the alternator while
the engine is running
2. Turn the ignition switch to the OFF position.
3. Disconnect the negative battery cable.
4. Use the special tool (Alternator test harness:
MB991519, MB991450) to connect a digital
voltmeter between the alternator S terminal and
earth. (Connect the (+) lead of the voltmeter
to the "S" terminal, and then connect the (−)
lead of the voltmeter to a secure earth or to
the battery (−) terminal.)
5. Disconnect the alternator output wire from the
alternator "B" terminal.
6. 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.)
7. Reconnect the negative battery cable.
8. Connect a tachometer or the MUT-II.
9. Turn the ignition switch to the ON position and
check that the reading on the voltmeter is equal
to the battery voltage.
Voltage Regulation Table
Standard value:
Inspection terminal
Terminal "S"
ENGINE ELECTRICAL –
Voltage regulator ambient temperature _C
– 20
20
60
80
Charging System
NOTE
If the voltage is 0 V, the cause is probably an
open circuit in the wire or fusible link between
the alternator "S" terminal and the battery (+)
terminal.
10. Turn all lamps and accessories off.
11. Start the engine.
12. Increase the engine speed to 2,500 r/min.
13. Read the value displayed on the voltmeter when
the alternator output current alternator becomes
10 A or less.
14. If the voltage reading conforms to the value
in the voltage regulation, then the voltage
regulator is operating normally.
If the voltage is not within the standard value,
there is a malfunction of the voltage regulator
or of the alternator.
15. After the test, lower the engine speed to the
idle speed.
16. Turn the ignition switch off.
17. Remove the tachometer or the MUT-II.
18. Disconnect the negative battery cable.
19. Disconnect the ammeter and voltmeter.
20. Connect the alternator output wire to the
alternator "B" terminal.
21. Remove the special tool, and return the
connector to the original condition.
22. Connect the negative battery cable.
Voltage V
14.2 – 15.4
13.9 – 14.9
13.4 – 14.6
13.1 – 14.5
16-11