Set Appliance State:

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

Measurement:

Measure the resistance of the pump across Live and Neutral, and then Live and Earth.
Expected resistance.
Test 1:
Live to Neutral - 170 Ohms or greater
Test 2:
Live to Earth - Open Circuit