Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove the connector from the fan assembly
Remove connector X2 from the PCB

Measurement:

Test 1.
Measure the resistance between pin 4 (green) and
pin 10 (green) on connector X2.
Test 2.
Measure the resistance between pin 4 (green) and pin 10 (green) on
connector X2 individually to a suitable earth point.
Expected resistance greater than 1 MOhm for each test.
Note.
A reading of O.L is acceptable as this is greater than 1 MOhm.