BATTERY SYSTEM DIAGNOSIS
CONDITION
POSSIBLE CAUSES
CORRECTION
THE BATTERY STATE OF
CHARGE CANNOT BE
MAINTAINED.
1. The battery has an incor-
rect size or rating for this
vehicle.
1. Refer to Battery System Specifications for the
proper specifications. Replace an incorrect bat-
tery, as required.
2. The battery terminal con-
nections are loose or cor-
roded.
2. Refer to Battery Cable for the proper cable
diagnosis and testing procedures. Clean and
tighten the battery terminal connections, as re-
quired.
3. The electrical system igni-
tion-off draw is excessive.
3. Refer to the IGNITION-OFF DRAW TEST
Standard Procedure for the proper test proce-
dures. Repair the faulty electrical system, as re-
quired.
4. The battery is faulty.
4. Test the battery using the Micro 420 battery
tester. Refer to Standard Procedures for addi-
tional test procedures. Replace the faulty bat-
tery, as required.
5. The starting system is
faulty.
5. Determine if the starting system is performing
to specifications. Refer to Starting System for
the proper starting system diagnosis and testing
procedures. Repair the faulty starting system, as
required.
6. The charging system is
faulty.
6. Determine if the charging system is perform-
ing to specifications. Refer to Charging System
for additional charging system diagnosis and
testing procedures. Repair the faulty charging
system, as required.
7. Electrical loads exceed
the output of the charging
system.
7. Inspect the vehicle for aftermarket electrical
equipment which might cause excessive electri-
cal loads.
8. Slow driving or prolonged
idling with high-amperage
draw systems in use.
8. Advise the vehicle operator, as required.
THE BATTERY WILL NOT
ACCEPT A CHARGE.
1. The battery is faulty.
1. Test the battery using the Micro 420 battery
tester. Charge or replace the faulty battery, as
required.
ABNORMAL BATTERY DISCHARGING
Any of the following conditions can result in abnor-
mal battery discharging:
1. A faulty or incorrect charging system compo-
nent. Refer to Charging System for additional charg-
ing system diagnosis and testing procedures.
2. A faulty or incorrect battery. Use Micro 420 bat-
tery tester and refer to Battery System for additional
battery diagnosis and testing procedures.
3. A faulty circuit or component causing excessive
ignition-off draw.
4. Electrical loads that exceed the output of the
charging system. This can be due to equipment
installed after manufacture, or repeated short trip
use.
5. A faulty or incorrect starting system component.
Refer to Starting System for the proper starting sys-
tem diagnosis and testing procedures.
6. Corroded or loose battery posts and/or terminal
clamps.
7. Slow driving speeds (heavy traffic conditions) or
prolonged idling, with high-amperage draw systems
in use.
8F - 4
BATTERY SYSTEM
VA
