Set Appliance State:
Set Multimeter to Resistance 
Isolate Mains Power to appliance as per TOPs P4
Disconnect the leads from the ON/OFF switch, noting their connections
ON/OFF switch ON
Disconnect the leads from the ON/OFF switch, noting their connections
ON/OFF switch ON
Measurement:
Test 1:
Measure resistance across the two back connectors (marked E and marked D).
Test 2:
Measure resistance across the two front connectors (also marked E and D).
Measure resistance across the two back connectors (marked E and marked D).
Test 2:
Measure resistance across the two front connectors (also marked E and D).
Isolate as per TOPs P4
and refit as necessary