Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Disconnect mains supply electrical plug from the pump (left side)

Measurement:

Test 1:
Measure the resistance between the
left and right pins at the pump.
Resistance should be greater than 1M Ohm.
Test 2:
Measure the resistance between the
right hand pin to a suitable earth point.
Resistance should be greater than 1M Ohm.