Set Appliance State:

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

Measurement:

Test 1:
Measure the resistance between the L and N connections at the pump.
Resistance should be approximately 160 Ohms or greater.
Test 2:
Measure the resistance between the L and earth connections at the pump.
Resistance should be greater than 1MOhm.