Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove connector at top of pump

Measurement:

Check for continuity between the live wire of the pump connector to pin 5 (brown) of connector J3 on the control PCB and from the neutral wire of the pump connector to pin 4 (blue) of J3.
Also inspect the overall harness condition.