Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Disconnect wires from pump

Measurement:

Test 1:
Measure the resistance across pump L and N
Resistance will vary by pump but should be above 80 Ohms.
Test 2:
Measure the resistance across pump L and pump earth.
Resistance should be greater than 1M Ohm.
Test 3:
Measure the resistance across pump N and pump earth.
Resistance should be greater than 1M Ohm.