TM 9-2320-211-20
T a b l e 2-4. Troubleshooting--Electrical System-Continued
Item
Probable Cause
Malfunction
Corrective
Action
No.
GENERATOR SYSTEM--Continued
Replace or adjust the drive belts.
a. Broken or loose drive belts.
10 Generator does not charge.
Replace the generator-regulator if
b. Faulty voltage regulator
required. Polarize the generator
(para 2 - 1 3 1 ) .
Replace the generator if required
c. Faulty generator
the
Polarize
generator (para 2-131).
Replace the generator-regulator if
11 G e n e r a t o r output excessive
a. Faulty voltage regulator
required (para 2-131). Polarize the
( b a t t e r y - g e n e r a t o r indicator
generator.
almost on extreme right of meter
Replace the generator (para 2-131).
scale).
b. Faulty generator
Polarize the generator (para 2-
Tighten the drive belt (para 2-131).
12 Generator output low or unsteady
a. Loose drive belt
Check circuits No. 8 and 4 for
indicator
(battery-generator
b. Loose connections in battery-to-
continuity and tightness.
fluctuates between low and
generator or voltage regulator
medium charge with engine
circuit.
Replace the generator-regulator if
c. Faulty voltage regulator
operating).
required (para 2-131). Polarize the
generator (para 2-131).
Replace the generator (para 2-131).
d. Sticky brushes or rough com-
Polarize the generator (para 2-
mutator
Replace the lamp (para 2-155).
a. Broken or burned out lamp.
13 Headlights do not light.
Use a jumper wire across the switch
b. Defective light switch
contacts. If the lamp lights, replace
the switch (para 2-155).
Refer to the lighting circuit diagram.
c. Broken light cable
Locate the break and repair the
cable as necessary.
Replace the regulator (para 2-132).
14 Frequent lamp failures. High
a. Generator-regulator out of ad-
indicator
battery-generator
justment.
Clean and tighten the battery and
b. Poor battery ground connection.
reading.
lamp ground connections.
Clean and tighten the battery and
15 Insufficient light. Low battery-
a. Poor lamp or battery ground
lamp ground connections.
connections.
generator indicator reading.
Locate and tighten the loose terminal
b. Loose lamp terminals connections.
connections.
Check the electrolyte level and
c. Discharged batteries
specific gravity (para 2-22). Charge
or replace the batteries (para 2-
Replace bulb
16 Turn signals do not blink (on
a. Bulb (front or rear) burned out.
Replace flasher
vehicle outside).
b. Flasher defective
17 Turn signals totally inoperative.
Replace flasher
Flasher defective
Replace lamp
18 Turn signal indicator (in cab)
a. Lamp defective
Replace flasher
b. Flasher defective
does not blink.
19 Floodlights do not respond to light
Replace lamps (para 2-133) or switch
a. Lamps burned out; faulty switch.
switch.
N o t i f y supporting maintenance
b. Faulty circuit, or wiring, or
personnel.
defective light assembly defec-
tive.
N o t i f y supporting maintenance
c. Brush slipring assembly defective.
personnel.
INSTRUMENTS, GAGES
AND SENDING UNITS
Replace
flexible shaft (para 2-150, 2-
Binding or kinked flexible shaft.
20 Speedometer or tachometer noisy
151).
or fluctuating.
Replace
sending unit (para 2-167).
a. Temperature sending unit faulty.
2 1 Water temperature gage in-
Replace
gage (para 2-153)
b. Gage faulty
operative.
Replace
the sending unit (para 2-
a. Fuel tank sending unit faulty.
162).
Replace
the gage (para 2-146)
b. Gage faulty
2-22
