Fault Phenomenon: LiuGong HBT60 dashboard displays normally when cold. After working for 1 hour (operating temperature), the dashboard goes black, all lights go out, but the engine continues to run.

Troubleshooting Process:
– Checked main power fuse: fuse intact, not blown.
– Checked generator output voltage: stable at 28V, charging normal.
– Checked key switch wiring: wiring intact, connections secure.
– Measured key switch output at operating temperature: found ignition switch internal contacts open due to heat.

Root Cause: Internal plastic parts of the combination switch deform due to heat, causing an open circuit.

Required Parts: Multi-function combination switch assembly.