Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect the blue and purple leads from the fan
Disconnect the 5 pin plug at the PCB
Disconnect the 5 pin plug at the PCB
Measurement:
Measure resistance from the purple lead from fan to purple connector at the 5 pin plug and from the blue lead from fan to blue connector at the 5 pin plug.
Continuity should be measured.
Also inspect the fan harness for good general condition.
Continuity should be measured.
Also inspect the fan harness for good general condition.
Isolate as per TOPs P4
and refit as necessary