Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Disconnect fan connector ST5 from the PCB

Measurement:

Test 1:
Measure resistance between the wires in the
harness as listed in the table below.
Expected resistances as below.
Test LeadsResistance in Ohms
Brown - purpleGreater than 1 MOhms
Brown - OrangeGreater than 1 MOhms
Brown - YellowGreater than 1 MOhms
Brown - WhiteGreater than 1 MOhms

Test 2:
Measure the resistance between each of the wires in the connector and earth.
Expect open circuit for each test.