TM 5-3895-382-24
b.
The battery voltage is less than the voltage in
Table 29.
Refer to Special Instruction, SEHS7633 in order to
test the battery.
A low charge in a battery can be caused by several
conditions.
Deterioration of the battery
A shorted starting motor
A defective alternator
Loose drive belts
Current leakage in another par of the electrical system
3.
Measure the current that is between the positive battery
post and the starting motor solenoid. Use the 8T-0900
Ammeter. Refer to the Specifications, "Starting Motor"
for the maximum current that is allowed for no load
conditions.
NOTE:
If the following conditions exist, do not perform
the test in Step 3 because the starting motor has a
problem.
The voltage at the battery post is within 2 volts of the
lowest value in the applicable temperature range of
Table 29.
The large starting motor cables get hot.
The current and the voltages the are specified in the
Specifications module are measured at a temperature of
27C (80F). When the temperature is below
27C (80F), the voltage will be lower through the
starting motor. When the temperature is below
27C (80F), the current through the starting motor will
be higher. If the current is too great, a problem exists in
the starting motor. Repair the problem or replace the
starting motor.
4.
Use the multimeter in order to measure the voltage of
the starting motor. Measure the voltage from test point
(4) to test point (5) when you are cranking or attempting
to crank the engine.
5.
Voltage across test points (4) and (5).
a.
If the voltage is equal to the voltage that is given in
Table 29 or if the voltage is greater than the voltage
that is given in Table 29, then the battery and the
starting motor cable that goes to the starting motor
are within specifications. Go to Step 8.
b.
The starting motor voltage is less than the voltage
specified in Table 29.
The voltage drop between the battery and the starting
motor is too great. Go to Step 6.
6.
Measure the voltage drops in the cranking circuits with
the multimeter. Compare the results with the voltage
drops which are allowed in Table 30.
7.
Voltage drops in the cranking circuits.
a.
Voltage drops are equal to the voltage drops that are
given in Table 30 or the voltage drops are less than
the voltage drops that are given in Table 30. Go to
Step 8 in order to check the engine.
b.
The voltage drops are greater than the voltage drops
that are given in Table 30. The defective component
should be repaired or replaced.
8.
Rotate the crankshaft by hand in order to ensure that
the crankshaft is not stuck. Check the oil viscosity and
any external loads that could affect the engine rotation.
a.
If the crankshaft is stuck or difficult to turn, repair the
engine.
b.
If the engine is not difficult to turn, go to Step 10.
9.
Attempt to crank the starting motor.
a.
The starting motor cranks slowly.
Remove the starting motor for repair or replacement.
b.
The starting motor does not crank.
Check for the blocked engagement of the pinion gear
and flywheel ring gear.
NOTE:
Blocked engagement and open solenoid contacts
will give the same electrical symptoms.
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