Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove electrical connector from the diverter valve actuator and connector X19 from the PCB

Measurement:

Measure the resistance across each wire of the harness of removed diverter actuator connector and X19 connector.
Expect continuity / zero resistance on each wire.
Also visually inspect the condition of the wiring and connectors.
Note.
Ensure a good connection is made during resistance tests.