TM 9-2320-260-20
2-15. TEST EQUIPMENT
In troubleshooting the electrical system, multimeters will be used to make resistance or continuity
tests and voltage or low ampere current tests. Multimeters maybe found in the Common No. 1 or No. 2
Organizational Maintenance Automotive Shop Sets.
ELECTRICAL TROUBLESHOOTING
SYMPTOM INDEX
TROUBLESHOOTING
MALFUNCTION
MALFUNCTION
PROCEDURE
NO.
PAGE
BATTERY SYSTEM
All vehicle electrical systems inoperative. . . . . . . . . . . . . . . . . . . . . .
STARTING SYSTEM
Starter will not crank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starter motor operates, but engine cranks slowly. . . . . . . . . . . . . . . .
Starter motor operates, but engine will not start . . . . . . . . . . . . . . . .
CHARGING SYSTEM (60 AMP)
No alternator output (voltmeter in left-hand red). . . . . . . . . . . . . . . .
Batteries not charging properly
(voltmeter in yellowor right-hand red) . . . . . . . . . . . . . . . . . . . . .
Batteries hot or boiling, corrected specific. gravity of
all cells is 1.280 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Batteries use excessive water.... . . . . . . . . . . . . . . . . . . . . . . . . . .
Batteries rundown inoperation. . . . . . . . . . . . . . . . . . . . . . . . . . . .
CHARGING SYSTEM (100 AMP)
No alternator output (voltmeter in left-hand red). . . . . . . . . . . . . . . .
Batteries not charging properly
(voltmeter in yellow or right-hand red) . . . . . . . . . . . . . . . . . . . . .
Batteries hot or boiling, corrected specific gravity of
all cells is 1.280 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Batteries use excessive water.... . . . . . . . . . . . . . . . . . . . . . . . . . .
Batteries rundown inoperation. . . . . . . . . . . . . . . . . . . . . . . . . . . .
LIGHTING SYSTEM
Headlight does not operate on low or high beam, or both
headlights inoperative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front marker lampdoesnotlight. . . . . . . . . . . . . . . . . . . . . . . . . . .
Taillight or clearance lamp does not light . . . . . . . . . . . . . . . . . . . . .
Stoplight lamp does not light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Blackout headlamp does not light . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front blackout marker lamp does not light . . . . . . . . . . . . . . . . . . . .
Blackout taillight lamp does not light. . . . . . . . . . . . . . . . . . . . . . . .
Blackout stoplight lamp does not light . . . . . . . . . . . . . . . . . . . . . . .
Directional signal inoperative . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
All stoplights are inoperative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Both directional signals inoperative . . . . . . . . . . . . . . . . . . . . . . . . .
Turn signals operate incorrectly with turn signal
control lever inoneor more positions. . . . . . . . . . . . . . . . . . . . . . .
One or more floodlights do not operate . . . . . . . . . . . . . . . . . . . . . . .
Warning lamp fails cooperate . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-97
