Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect the 4 wire plug from the Fan
Measurement:
Measure for continuity (zero resistance) between the ends
of the 4 wires, in turn, at connector X23 on the PCB to the corresponding colour at the disconnected plug.
Inspect the harness and connectors for good overall condition.
of the 4 wires, in turn, at connector X23 on the PCB to the corresponding colour at the disconnected plug.
Inspect the harness and connectors for good overall condition.
Isolate as per TOPs P4
and refit as necessary