Service Manual

Electrical System Quick Checks
Battery Test (Open Circuit Test)
Use a multimeter to measure the voltage between the
battery terminals.
Set the multimeter to the DC volts setting. The battery
should be at a temperature of
60
o
to 100
o
F (16
o
to 38
o
C). The ignition key should be in the OFF position and
all accessories turned off. Connect the positive (+) me-
ter lead to the positive battery post and the negative (–)
meter lead to the negative battery post. Use the table to
the right to determine charge level of the battery.
NOTE: This test provides a relative condition of the bat-
tery
. Load testing of the battery will provide additional
and more accurate information.
Voltage Measured Battery Charge Level
12.68 v (or higher) Fully charged (100%)
12.45 v 75% charged
12.24 v 50% charged
12.06 v 25% charged
11.89 v 0% charged
Charging System Test
This is a simple test used to determine if the charging
system is functioning. It will tell you if the charging sys-
tem has an output, but not its capacity.
Use a multimeter set to the DC volts position. Connect
the positive (+) meter lead to the
positive battery post
and the negative (–) meter lead to the negative battery
post. Leave the multimeter test leads connected to the
battery and record the battery voltage.
NOTE: Upon starting the engine, the battery voltage
will drop and then should increase once the engine is
running.
NOTE: Depending
upon the condition of the battery
charge and battery temperature, the charging system
voltage will increase at different rates as the battery
charges.
Start the engine and run at 3600 RPM (high idle). Allow
the battery to charge for at least 3 minutes. Record the
battery voltage.
After allowing the engine to run for at least three (3) min-
utes, battery voltage should be at least 0.5 volts higher
than initial battery voltage (see example in table to the
right).
NOTE: While
engine is running, if battery voltage ex-
ceeds 15 volts, the regulator in the charging system
should be inspected (see the engine Repair Manuals lo-
cated after Chapter 3).
After allowing the engine to run for at least three (3) min-
utes, if battery voltage does not increase at least 0.5
volts, additional testing of the battery and/or charging
system should be performed.
Greens Aerator
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Acceptable voltage increase:
Initial Battery Voltage = 12.25 v
Battery Voltage after 3 Minute Charge = 12.80 v
Difference = +0.55 v
Electrical
System
Electrical System