Fault Phenomenon: JLG 3246ES scissor lift aerial work platform pressing the emergency stop button, the vehicle does not cut power, and can still operate.

Troubleshooting Process:
– Checked emergency stop switch: switch internal contacts stuck.
– Checked wiring: wiring shorted, bypassing the switch.
– Checked contactor: contactor main contacts welded.
– Checked control logic: PLC program error.

Root Cause: The emergency stop switch internal contacts are welded and stuck, unable to open the control circuit.

Required Parts: Emergency stop button assembly.