Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove connector X13 from the PCB

Measurement:

Test 1.
Measure for resistance across pins 1 & 2 of connector X13.
Expected resistance 20 - 30 Ohms.
Test 2.
Measure for resistance across pins 3 & 4 of connector X13.
Expected resistance 60 - 70 Ohms.