TM-9-2320-280-20-1
TRUCK, UTILITY: M998 SERIES
TECHNICAL MANUAL; UNIT MAINTENANCE; VOLUME 1 OF 3
JANUARY 1996
TM-9-2320-280-20-1 - Page 309 of 888
2-224
Change 2
TM 9-2320-280-20-1
ALTERNATOR
DIAGNOSTIC FLOWCHART
F4
TEST OPTIONS
1. STE/ICE Test 89,
(page 2-750)
2. Multimeter
REASON FOR QUESTION
Wire 568A and wire 568
carry ignition current to turn
on regulator.
TEST OPTIONS
STE/ICE Test 10 and 90,
(pages 2-734 and 2-751).
REASON FOR QUESTION
This connection applies full
current loading to field coil.
Alternator current output
should be near maximum.
F5
NO
YES
REPLACE WIRE
568
FROM F3,
Page 2-222
CONNECT WIRE 568A AND 568.
DISCONNECT WIRE 568 FROM
ALTERNATOR. TURN ROTARY
SWITCH TO “RUN”. MEASURE
VOLTAGE AT ALTERNATOR END
OF WIRE. IS THERE VOLTAGE AT
BATTERY END OF WIRE 568?
DISCONNECT ALTERNATOR-TO-
REGULATOR CABLE. START
ENGINE AND SET IDLE 1200-1500
RPM. USING 15 AMP CAPACITY
JUMPER WIRE, MOMENTARILY
CONNECT PIN A OF ALTERNATOR
CONNECTOR TO ENGINE
GROUND. DOES CURRENT RISE
DURING CONNECTION TO 90-110
AMPS?
NO
YES
REPLACE ALTERNATOR,
(Para. 12-24).
THEN GO TO
Step 5, Page 2-198
REPLACE REGULATOR,
(Para. 12-22).
THEN GO TO
STEP 5,
Page 2-198.
KNOWN INFO
VOLTAGE OUTPUT
INCORRECT
REGULATOR HAS
ENERGIZING
VOLTAGE
POSSIBLE PROBLEMS
ALTERNATOR
REGULATOR
WIRE
KNOWN INFO
VOLTAGE OUTPUT
INCORRECT
REGULATOR HAS
ENERGIZING
VOLTAGE
POSSIBLE PROBLEMS
ALTERNATOR
REGULATOR
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