Fault Phenomenon: Komatsu WA320 wheel loader battery frequently drains; generator output voltage is unstable or zero.

Troubleshooting Process:
– Checked diodes: multimeter measurement shows rectifier diode shorted.
– Checked windings: stator windings burnt.
– Checked regulator: voltage regulator failed.
– Checked belt: belt normal.

Root Cause: A diode in the generator’s internal rectifier bridge broke down due to overload or aging, preventing AC from being properly converted to DC or causing reverse discharge.

Required Parts: Replace generator rectifier bridge or generator assembly.