Fault Phenomenon: Putzmeister M72 electrical system functions normally when cold. Under high-current load (operating temperature), the wiring harness connector melts, a burning smell occurs, and eventually an open circuit.

Troubleshooting Process:
– Checked load current: current not exceeding rating.
– Checked connector type: type matches.
– Checked crimp quality: crimp secure.
– Measured connector contact resistance at operating temperature: found excessive resistance.

Root Cause: Oxidation of the connector terminals causes excessive heat generation under high current, leading to melting.

Required Parts: Wiring harness connector and terminal repair kit.