Dodge RAM TRUCK 1500 1995 Service Manual page 340

B R BATTERY/ST1RTING/CHARGING SYSTEMS DIAGNOSTICS 8A - 7
Before performing load test, the battery must
be FULLY-CHARGED.
(1) Remove both battery cables, negative first. Bat­
tery top and posts should be clean.
(2) Connect a suitable volt-ammeter-load tester
(Fig. 6) to the battery posts (Fig. 7). Refer to operat­
ing instructions provided with the tester being used.
Check the open circuit voltage (no load) of the bat­
tery. Open circuit voltage must be 12.4 volts or
greater.
V C M J S E L E C T O R
n a n s a j a n o w
898A-8
Fig. 6 Volt-Amps-Load Tester - Typical
INDUCTION
AMMETER
CLAMP
POSITIVE
CLAMP
NEGATIVE
CLAMP
J948A-13
Fig. 7 Volt-Ammeter-Load Tester Connections
(3) Rotate the load control knob (carbon pile rheo­
stat) to apply a 300 amp load for 15 seconds, then re­
turn the control knob to OFF (Fig. 8). This will
remove the surface charge from the battery.
(4) Allow the battery to stabilize to open circuit
voltage. It may take up to 5 minutes for voltage to
stabilize.
(5) Rotate the load control knob to maintain a load
equal to 50% of CCA rating (Fig. 9). After 15 seconds,
record the loaded voltage reading, then return the
load control knob to OFF.
(6) Voltage drop will vary with battery tempera­
ture at the time of the load test. Battery temperature
can be estimated by the ambient temperature over
the past several hours. If the battery has been
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Fig. 9 Load 50% CCA Rating - Note Voltage
charged, boosted, or loaded a few minutes prior to
test, the battery will be somewhat warmer. See Load
Test Temperature chart for proper loaded voltage
reading.
(7) If the voltmeter reading falls below 9.6 volts, at
a minimum battery temperature of 21°C (70°F), re­
place the battery.
LOAD TEST TEMPERATURE
Minimum Voltage Minimum Voltage
P
e
9.6
70 and above 21 and above
9.5
60
16
9.4
50
10
9.3
40
4
9.1
30
-1
8.9
20 ~7
1
8.7 10
-12
8.5
0
-18
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