Komatsu 830E Shop Manual page 127

GO TO REGULATOR (IF REQUIRED)
Disconnect voltage regulator from alternator. There
are no static tests available for the regulator. Con-
tinue test.
GO TO REGULATOR
ALTERNATOR
Connect a jumper wire from ground on
alternator into "F-" pin of connector attached
to alternator. (See Figure 2-3.)
Hold a steel wrench or screwdriver near
alternator drive pulley; wrench or screwdriver
held near drive pulley will be attracted to
pulley by magnetism.
• If there is no attraction, alternator field is
defective. Replace alternator.
• If there is magnetic attraction, alternator field is
good. Continue test.
With jumper still connected between "B+"
terminal and "E" terminal on alternator: Insert
"+" probe of voltmeter into "E" terminal of
connector, and Ground negative probe of
voltmeter to alternator ground terminal.
• If meter shows no voltage, alternator is defective.
Replace alternator.
D02023
CONNECTOR ON
24 VDC Electric Supply System
FIGURE 2-4. ALTERNATOR TERMINALS
1. Control Unit
2. "R" Terminal
3. Link Strap
4. "E" Terminal
5. "B+" Terminal
6. Ground Terminal
• If meter shows battery voltage, circuit is good.
Continue test.
Insert "+" probe of voltmeter into "B" pin in
connector. Insert negative probe of voltmeter
into "B-" pin in connector. (This is power
circuit for voltage regulator.)
• If circuit shows open (no voltage), alternator is
defective. Replace alternator.
• If circuit shows B+ voltage, regulator is defective.
Replace REGULATOR ONLY.
NOTE: Turn key and battery switch OFF before
installing new regulator. Turn battery switch and key
back on AFTER installing new regulator. Continue
test.
Remove all jumper wires from alternator used to test
charging circuit. Reconnect link from "R" terminal to
"E" terminal
D2-9