Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove connector X11 from the PCB
Remove the AC fan connector (3 wire) from the fan assembly

Measurement:

Measure the resistance of each of the wires in the harness as below:
Brown wire on connector X11 to the brown wire on the fan connector.
Blue wire on connector X11 to the blue wire on the fan connector.
Green/Yellow wire on connector X11 to green/yellow on the fan connector.
Expect continuity on each of the tests.
Also inspect the condition of the harness visually for any signs of damaged insulation.