MOUNT AS 9R0390 - Caterpillar

Use this procedure to troubleshoot a problem with the charging system. Also, use this procedure if one of the following event codes is active or logged.Probable Causes
Belts
Pulley
Bearings
Operation
Charging circuitRecommended Actions
Table 1
Troubleshooting Test Steps Values Results
1. Inspect the Alternator Drive Belts
A. Inspect the condition of the alternator drive belts.
B. Check the belt tension and/or automatic belt tensioner.
Note: Excessive belt tension can result in damage to the alternator.
Belts
Result: The alternator drive belts and belt tensioner are OK.
Proceed to Test Step 2.
Result: The alternator drive belts and/or belt tensioner are NOT OK.
Repair: Repair or replace the damaged drive belts or belt tensioner.
If the problem is not resolved, proceed to Test Step 2.
2. Check the Condition of the Alternator Drive Pulley
A. Look for deep grooves that have been worn into the pulley by the belt.
B. Check that the nut for the pulley has not become loose.
Note: Make sure that the alignment is correct.
Pulley
Result: The alternator drive pulley is OK.
Proceed to Test Step 3.
Result: The alternator drive pulley is NOT OK.
Repair: Repair or replace the damaged alternator drive pulley.
If the problem is not resolved, proceed to Test Step 3.
3. Check the Alternator Bearings
A. Check the alternator bearings for signs of wear.
Bearings
Result: The alternator bearings are OK.
Proceed to Test Step 4.
Result: The alternator bearings are NOT OK.
Repair: Repair or replace the damaged alternator.
If the problem is not resolved, proceed to Test Step 4.
4. Check the Operation of the Alternator and Regulator
A. Verify that the alternator and/or the regulator is operating correctly. Refer to Special Instruction, REHS0354, "Charging System Troubleshooting" for additional information.
Operation
Result: The alternator and or regulator are operating correctly.
Proceed to Test Step 5.
Result: The alternator and/or regulator are not operating correctly.
Repair: Repair or replace the damaged alternator.
If the problem is not resolved, proceed to Test Step 5.
5. Inspect the Charging Circuit
A. Inspect the battery cables, wiring, and connections in the charging circuit.
B. Clean all connections and tighten all connections.
Charging Circuit
Result: The charging circuit is NOT OK.
Repair: Repair or replace the damaged charging circuit components.
Refer to Testing and Adjusting, "Charging System" for additional information.
Refer to Testing and Adjusting, "Battery" for additional information.
Verify that the repair eliminated the problem.
If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).