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 between each of the wires in the harness as below:
Brown wire on connector X11 to brown wire on the fan connector.
Blue wire on connector X11 to blue wire on the fan connector.
Earth wire on connector X11 to earth wire on the fan connector.
Expect continuity / zero resistance on each test.
Also visually inspect the condition of the harness.