Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove connector X3 from the PCB

Measurement:

Measure the resistance between the blue wire and black wire of connector X3.
Resistance should be approximately 115 Ohms.
Note:
Wires may be multicoloured e.g. blue & white.