Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Disconnect leads from terminals marked L and N in the section marked "PUMP" on the main terminal strip.

Measurement:

Test 1:
Measure resistance across the blue (pump neutral) and brown (pump live) leads that have been disconnected.
Resistance will vary by pump but should be above 80 Ohms.
Test 2:
Measure resistance across the disconnected blue lead (pump neutral) and earth.
Expected resistance open circuit.
Test 3:
Measure resistance from the disconnected brown lead (pump live) and earth.
Expected resistance open circuit.