Set Appliance State:

Set Multimeter to Resistance Set meter to measure resistance
Isolate Mains Power to appliance as per TOPs P4
Disconnect PCB connector PL4

Measurement:

Measure the resistance across the two Violet wires on the disconnected connector PL4.
The resistance measured should be an open circuit.
While measuring the resistance across the two Violet wires on the disconnected connector PL4, depress the Reset Switch.
The resistance measured should be a short circuit.
Ensure multimeter probes have good contact with violet wire connections.