Table 2-4. Troubleshooting--Electrical System--Continued
Item
Malfunction
Probable Cause
Corrective Action
No.
IGNITION SYSTEM--
GASOLINE ENGINE--Continued
Pre-ignition due to defective or
With engine temperature at normal
4 Engine does not attain maximum
operating range (160 F. to 180
improper spark plugs.
rpm.
F.), accelerate the vehicle in high
gear. If pre-ignition or spark knock
is present, a pinging sound will be
heard. After checking the ignition
system thoroughly, replace spark
plugs; if this does not correct the
condition, notify direct support
maintenance personnel.
STARTING SYSTEM
5 Starter inoperative
a. Batteries discharged.
Check electrolyte level and specific
.
gravity (para 2-22). Replace
defective batteries.
b. Loose, corroded, or broken cables.
Clean and tighten all electrical
connections at battery, ground, and
starter. Replace cable if they are
broken, or if a terminal clamp is
excessively corroded.
c. Defective solenoid
Replace the solenoid (para 2-126).
d. Defective starter switch
Check the linkage from the starter
pedal to the upper clevis of the
starter (gasoline engine). Energize
the starter switch for testing
purpose. Test the defective switch.
Replace the defective starter if
e. Defective starter motor
required (para 2-124).
6 Noisy starter
Tighten starter mounting screws.
a.
Loose starter mounting
Replace the starter (para 2-124).
b.
Defective drive assembly
Replace the starter (para 2-124).
c.
Worn commutator or bushings.
Replace the starter (para 2-124).
d.
Defective bearing due to lack of
lubrication.
7 Starter sluggish; will not attain
a. Discharged or defective batteries.
Check electrolyte level and specific
full cranking speed.
gravity (para 2-22). Recharge or
replace batteries as necessary (para
b. Dirty or loose terminals
Clean and tighten terminal con-
nections.
c. Sticking brushes; commutator or
Replace starter (para 2-124).
armature rubbing field coils.
8 Battery-generator indicator shows
Refer to item 5a above
a. Faulty batteries
low charge.
Add water to correct level.,Check the
b. Electrolyte level low in batteries.
.
battery-generator indicator for a
high reading.
Clean and tighten the battery ter-
c. Loose connection in generator-
minal connections, and check all
regulator or battery circuit.
connections in the circuit (fig. 2-
Replace the generator-regulator if
d. Generator-regulator out of ad-
required (para 2-132). Polarize the
justment.
generator (para 2-131). Notify
direct support maintenance per-
sonnel.
Tighten the generator mounting bolts
9 Noisy generator
a. Loose generator mounting
and adjust the drive belts (para 2-
Tighten the pulley
b. Generator drive pulley loose on
shaft.
c. Worn commutator, sticky brushes,
Replace the generator (para 2-131).
Polarize the generator (para 2-
or armature rubbing on field
coils.
2-21
