Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Disconnect the Connector from the Fan
Disconnect the Fan harness connector from the PCB

Measurement:

Measure the resistance of each of the wires in the harness From the PCB connector to the Fan connector.
Red to Red
Black to Black
Yellow to Yellow
Pink to Pink
Blue to Blue
Expect zero resistance or continuity for each wire in the harness.
Also inspect the harness visually.