Komatsu 830E Shop Manual page 123

FIGURE 2-2. TEST METER HOOKUP
1. Alternator Under Test
2. 0 to 400 AMP Ammeter
3. 0 to 40 VDC Voltmeter
4. Alternator "B+" Terminal
5. Alternator Ground Terminal
6. Truck Batteries
Regulator Bypass Test
If the test procedure outlined on the previous page
indicates low current output and low voltage out-
put, perform the following test to determine if the
voltage regulator is defective or if the alternator is
defective.
1. Disconnect alternator/regulator harness plug (5,
Figure 2-3).
2. Momentarily touch connector male pin "F-" to
ground.
3. Observe meter readings:
• If voltage or amperage rises, the alternator is OK.
The regulator is defective and should be
replaced.
D02023
• If grounding the harness male pin has no effect,
the alternator is defective and should be
replaced.
FIGURE 2-3. REGULATOR BYPASS TEST
24 VDC Electric Supply System
1. Alternator Control Unit
2. "R" Terminal (Relay)
3. "E" Terminal (Energize)
4. Alternator "B+" Terminal
5. Alternator/Voltage Regulator
Harness Plug
D2-5