Komatsu 830E-AC Shop Manual page 247

Test Procedure
The following tests require working near the
engine when it is on. Use caution when working
near the engine fan, alternator fan, and fan belts.
1. Start the engine and accelerate to high idle.
If the charge voltage is above 33-Volts, immedi-
ately shut the engine off. Electrical system dam-
age may occur if the charging system is allowed
to operate at high voltage.
D10003 07/06
2. Watch the meter reading(s). If the battery is suf-
ficiently discharged, the amps must be high
within ± 10% of the output specified by the per-
formance curve. Volts must be within or below
the normal range as the battery approaches full
charge. Amps must fall as the voltage rises.
When the amps and Volts stabilize, note the
readings and refer to Table 10-3.
Table 10-3: AMP/VOLTAGE READINGS
Amps
HIGH
HIGH
HIGH
LOW
LOW
LOW
3. The batteries are considered fully charged if the
charge voltage is at the regulator set point, and
the charge amps remain at the lowest value for
10 minutes.
4. If the charging system is not performing prop-
erly, go to the Regulator Bypass test in the next
section.
Battery Charging Alternator
Volts Diagnosis
LOW Charging system is good. Battery
is not yet fully charged. Wait for
charging system to bring to full
charge: Amps must decrease and
Volts must stabilize within normal
range.
NORMAL Watch until amps fall, or Volts
exceed normal range. If amps
decrease and Volts remain normal,
charging system is good. If Volts
exceed normal, regulator and/or
field coil must be replaced. Go to
Static Tests.
HIGH Stop the test. Regulator and/or
field coil replaced. Go to Static
Tests.
LOW Ensure voltmeter leads are
attached at the alternator. If the
connections are good, the alterna-
tor and/or regulator must be
repaired or replaced. Go to Bench
Test 3.
NORMAL Regulator is good. Go to Bench
Test 2.
HIGH Stop the test. If battery and voltme-
ter check good, the regulator and/
or field coil must be replaced.
D10-17