Service manual

6-16 Engine Electrical Engine
2006 LSSV Service Manual Supplement
Diagnostic Information and
Procedures
Diagnostic Starting Point – Engine
Electrical
Begin the system diagnosis by reviewing the system
Description and Operation. Reviewing the Description
and Operation information will help you determine the
correct symptom diagnostic procedure when a
malfunction exists. Reviewing the Description and
Operation information will also help you determine if the
condition described by the customer is normal
operation. Refer to Symptoms – Engine Electrical in
order to identify the correct procedure for diagnosing
the system and where the procedure is located.
Symptom List
Important: For vehicle no start condition, refer to
Diagnostic Starting Point – Engine Electrical and for
Starter Motor Diagnosis refer to Symptoms – Engine
Electrical in Engine Electrical in 2006 C/K Truck
Service Manual.
Refer to a symptom diagnostic procedure from the
following list in order to diagnose the symptom:
• Battery Inspection/Test (Optima)
• Battery Charging (Optima)
• 24V Generator Noise Diagnosis
• 24V Generator Inoperative
Battery Inspection/Test (Optima)
Diagnostic Aids
Caution: Refer to Battery Disconnect Caution in
Cautions and Notices.
Important:
• Verify that all battery connections are clean and
torqued to fastener specification.
• Use the Out of Vehicle test for each battery in
the system.
Follow these instructions in order to avoid an incorrect
diagnosis:
1. Disconnect the negative battery cables. Refer to
the Battery Cable Disconnect/Connect
Procedure.
2. Install the test adapters on the terminals.
3. Follow the instructions for testing a removed
battery.
Important: Use the correct terminal adapters. Do not
use any common bolts or a combination of bolts, of
nuts, and of washers as adapters when testing the
battery. Use the test adapters that are provided with the
J 42000 or GM P/N 12303040 terminal adapters. If the
adapters that are provided with the J 42000 require
replacement, use GM P/N 12303040. Any other
adapter may not contact the correct areas of the battery
terminal, causing a resistance that may result in an
invalid battery test result.
4. Replace the battery only if the second test
shows a REPLACE BATTERY or BAD CELL-
REPLACE result.
Battery Charging (Optima)
Tools Required
J 42000 Battery Tester
• Only use a voltage regulated charger
• The charging area should be well ventilated.
• Do not charge a battery that appears to be
frozen; allow the battery to warm to room
temperature and test it using the J 42000 before
charging.
Recommended Charging Rates
Use the following values when charging the battery.
Battery Charger: 14.8 volts, 13.75 amps maximum,
and 24 hours maximum. Until charging amperage is
below 0.5 amp.
Constant Voltage: 14.7 to 15.0 volts, temperature
122°F (50°C), no current limits, continue until current
falls below 1 amp, then finish with 2 amp constant
current for 1 hour.
Float Charge: 13.2 to 13.8 volts, 1 amp maximum
current, time indefinite.
Charging Procedure
Notice: Turn OFF the ignition when connecting or
disconnecting the battery cables, the battery charger or
the jumper cables. Failure to do so may damage the
PCM or other electronic components.
1. Disconnect the battery cables. Refer to Battery
Cable Disconnect/Connect Procedure.
2. Ensure that all of the battery terminals are
clean.
3. Connect the battery charger per manufacturer’s
operating recommendations.
4. Turn ON the charger and set the charging
voltage. Refer to Recommended Charging
Rates.
5. Inspect the battery every half hour after starting
the battery. Estimate the battery temperature by
feeling the side of the battery.
Tip: If it feels hot to the touch or its temperature is over
45° C (125° F), discontinue charging and allow the
battery to cool before resuming charging.
6. After charging, test the battery. Refer to Battery
Inspection/Test (Optima).