Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Disconnect wires from APS, making a note of the connections

Measurement:

Measure the resistance across the common and
normally open connections at the APS.
(where the two wires were previously connected).
Expected resistance open circuit.
Note:
APS may differ in appearance but test remains the same.