Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove connector X20 from the PCB

Measurement:

Measure the resistance between pin 12 (black)
and pin 13 (black) on connector X20.
Expect continuity / zero resistance.
Note:
Each pin on the PCB connector is numbered.