Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove clock harness from PCB

Measurement:

Check for continuity (zero resistance) between the ends of each of the 4 wires (red, black, white and green) of the harness.
Expect continuity / zero resistance on each test.
Check the harness fits securely to the clock and PCB and is in good overall condition.