Fault Phenomenon: Caterpillar 966 wheel loader while running, the instrument shows battery discharge warning, low voltage.

Troubleshooting Process:
– Checked belt: generator belt broken or slipping.
– Checked wiring: excitation circuit open.
– Checked regulator: voltage regulator failed.
– Checked armature: internal generator windings burnt.

Root Cause: The generator belt tensioner pulley seized, causing the belt to break and the generator to stop running.

Required Parts: Generator belt and tensioner pulley assembly, inspect generator.