Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove connector CN7 from the interface PCB
Remove connector CN8 from the interface PCB

Measurement:

Test 1:
Measure the resistance between pin 4 on CN7 and pin 4 on CN8.
Expect continuity.
Test 2:
Measure the resistance between pin 6 on CN7 and pin 5 on CN8
Expect approximately 3.3 KOhms.