LIFTING GP 3921517 - Caterpillar

Probable Causes
Loose alternator drive belt
Loose alternator drive pulley
Charging circuit
Regulator is defective
Rectifier is defective
Brushes are worn or dirtyRecommended Actions
Loose Alternator Drive Belt
Inspect the condition of the alternator drive belts. If the alternator drive belts are worn or damaged, replace the belts.
Check the tension on the alternator drive belts. Adjust the tension, if necessary.Loose Alternator Drive Pulley
Check the key groove in the pulley for wear. If the groove is worn, install a new pulley. Tighten the pulley nut to the correct torque. Refer to Specification for the correct torque.Charging Circuit
Inspect the battery cables, wiring, and connections in the charging circuit. Clean all connections and tighten all connections. Replace any faulty parts.Regulator is Defective
Install a new regulator assembly.Rectifier is Defective
Install a new rectifier.Brushes are Worn Or Dirty
Install new brushes.