Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove the pump connector ST4 from the PCB

Measurement:

Test 1.
Measure the resistance between Live (Brown) and
Neutral (Blue) on connector ST4.
Test 2.
Measure the resistance between Live (Brown) on
connector ST4 to a suitable earth point.
Expect a resistance of greater than 1 MOhm for each test.
Note.
A reading of O.L is acceptable as this is greater than 1 MOhm.