MAINTENANCE OF THE M88A1 - OD1672 - LESSON 3/TASK 2
TABLE 1.
SPECIFIC GRAVITY - COLD CLIMATE.
Specific Gravity
Electrolyte Freezing
(corrected to 80F)
Temperature
1.100
+19 F
1.150
+5 F
1.200
-16 F
1.250
-62 F
1.280
-90 F
(2) Use the DC scale of the multimeter and check the battery voltage.
The open circuit terminal voltage of each battery should be 12 volts or
more.
(3)
Use the DC scale on the multimeter and check the battery terminal
voltage
while cranking the engine. The terminal voltage while cranking the
vehicle
for 10 seconds (with all electrical systems turned off) should not
be less
than 18 volts.
In this example, this battery serviceablilty test revealed that the
batteries are serviceable and are not the cause of the engine cranking
slowly and not starting. The next step in the troubleshooting procedure is
to fault isolate the starter system.
The fault isolation procedure is
described in the following subparagraphs.
Step 2.
Fault isolating any of the M88A1 electrical systems requires the
use of a pertinent electrical system diagram plus the appropriate test
equipment.
The fault isolation procedure described below is based on the
use of the starting system diagram (figure 37 on the following page) and a
multimeter.
(a) Disconnect circuit 14 at the bulkhead disconnect.
Place the
transmission selector in the PARK position.
Depress the START switch
(figure 28, view C, on page 66) and at the same time measure the voltage
from the bulkhead disconnect receptacle pin A to ground.
The voltmeter
should read 24 vdc.
(b) Since the voltmeter on the multimeter reads 24 vdc, reconnect
circuit 14 at the bulkhead disconnect. Disconnect circuit 14 at the engine
disconnect.
Depress the START switch and at the same time measure the
voltage from the engine
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