Set Appliance State:

Set Multimeter to Resistance Set meter to measure resistance
Isolate Mains Power to appliance as per TOPs P4
Selector Switch Winter position
Unplug connector CN4

Measurement:

Selector Switch Off:
Check for open circuit resistance across the Selector microswitch (Black wires)
on connector block CN4.
Selector Switch On:
Check for short circuit resistance across the Selector microswitch (Black wires)
on connector block CN4.
Note:
Test to be carried out at disconnected connector.