Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Hinge down the PCB housing
Remove the connectors from the fan and the PCB
Measurement:
Measure the continuity, in turn, between the brown, green and white wires at the connectors either end of the harness.
Expect continuity (zero resistance) on each wire.
Expect continuity (zero resistance) on each wire.
Isolate as per TOPs P4
and refit as necessary