PANEL 5T8566 - Caterpillar

Probable Causes
Alternator drive belt and tensioner
Alternator mounting bracket
Alternator drive pulley
Alternator bearings
Alternator
Charging circuitRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in order.
Table 1
Troubleshooting Test Steps Values Results
1. Condition of the Alternator Drive Belts
A. Inspect the condition of the alternator drive belts.
B. Check the belt tension. If the engine is equipped with an automatic belt tensioner, check the automatic belt tensioner.
Excessive belt tension can result in damage to the alternator.
Drive Belt
Result: The alternator drive belts are in good condition and the belt tension is correct.
Proceed to Test Step 2.
Result: The alternator drive belts are not in good condition or the belt tension is incorrect.
Repair: If the alternator drive belts are worn or damaged, replace the belts. Refer to Disassembly and Assembly for the correct procedure.
If necessary, replace the automatic belt tensioner. Refer to Disassembly and Assembly for the correct procedure.
2. Alternator Mounting Bracket
A. Inspect the alternator mounting bracket for cracks and distortion.
Alternator Mounting Bracket
Result: The alternator mounting bracket is cracked and distorted.
Repair the mounting bracket or replace the mounting bracket.
Note: The repair/replacement will ensure that the alternator drive belt and the alternator drive pulley are in alignment.
Result: The alternator mounting bracket is OK.
Proceed to Test Step 3.
3. Condition of the Alternator Drive Pulley
A. Check the condition of the alternator drive pulley. Look for deep grooves that have been worn into the pulley by the belt. Check that the nut for the pulley has not become loose.
Alternator Drive Pulley
Result: There is excessive wear on the alternator drive pulley.
Repair: Replace the pulley.
Result: The alternator drive pulley nut was loose.
Repair: Tighten the nut.
Result: There is not excessive wear on the alternator drive pulley.
Proceed to Test Step 4.
4. Wear of the Alternator Bearings
A. Check the alternator bearings for signs of wear.
Alternator Bearings
Result: The alternator bearings are OK.
Proceed to Test Step 5.
Result: The alternator bearings are not OK.
Repair: Repair the alternator or replace the alternator, as needed. Refer to Disassembly and Assembly for the correct procedure.
5. Operation of the Alternator or Regulator
A. Verify that the alternator or the regulator is operating correctly. Refer to Special Instruction, REHS0354, "Charging System Troubleshooting" for the proper testing procedures.
Regulator and Alternator
Result: The regulator and alternator are operating correctly.
Proceed to Test Step 6.
Result: The regulator and alternator are not operating correctly.
Repair: Repair the alternator and regulator or replace the alternator and regulator, as needed. Refer to Disassembly and Assembly for the correct procedure.
6. Inspection of the Charging Circuit
A. Inspect the battery cables, wiring, and connections in the charging circuit.
Charging Circuit
Result: The charging circuit is not working correctly.
Repair: Clean all connections and tighten all connections. Replace any faulty parts.
Result: The charging circuit is working correctly.
Contact the Dealer Solutions Network (DSN).