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 311 of 888
2-224.2
Change 1
TM 9-2320-280-20-1
ALTERNATOR
DIAGNOSTIC FLOWCHART
F.1-1
TEST OPTIONS
Visual
REASON FOR QUESTION
Must know model of alternator to
perform proper tests.
TEST OPTIONS
STE/ICE-R TEST 10,
(interleave with control
function 01 of page 2-734
then 89, page 2-750)
REASON FOR QUESTION
Determine if high or low output
voltage.
F.1-2
NO
YES
See note on
opposite page
IS THIS A NIEHOFF 100 AMP DUAL
VOLTAGE ALTERNATOR?
START ENGINE AND ALLOW TO
IDLE AT 1200 - 1500 RPM FOR 2 - 3
MINUTES.
NO
YES
If
output volt-
age is over 30.5
volts, replace reg-
ulator
(Para. 4-5.6).
F. 1
FROM B1
Page 2-204
TEST OPTIONS
STE/ICE-R 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.
F.1-3
DISCONNECT ALTERNATOR-TO-
REGULATOR CABLE. START
ENGINE AND SET IDLE 1200 - 1500
RPM. USING 15-AMP CAPACITY
JUMPER WIRE, MOMENTARILY
CONNECT TO ENGINE GROUND.
DOES CURRENT AND VOLTAGE
RISE
DURING CONNECTION?
NO
YES
Replace
regulator
(Para. 4-5.6). Then go
to 5, page 2-198
Replace
regulator (Para. 4-5.6).
Then go to 5,
page 2-198
KNOWN INFO
Voltage Incorrect
POSSIBLE PROBLEMS
Wiring
Alternator
Regulator
KNOWN INFO
Voltage Output
Incorrect
Regulator has
Energizing Voltage
POSSIBLE PROBLEMS
Alternator
Regulator
Wiring
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