Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove connector X9 from the PCB
Remove the connector from the diverter valve motor

Measurement:

Measure the resistance of each of the wires in the harness.
Expect continuity / zero resistance on each test.
Also visually inspect the condition of the harness and its connectors.