Set Appliance State:
Mains Power Off
| Isolate Mains Power to appliance as per TOP's P4 |
Remove 1 connector from the right hand switch (pink leads)
Measurement:
Measure the resistance across the summer/winter switch (right hand with pink leads).
Test 1
With switch in its (OFF) out position - expect open circuit.
Test 2
With switch in its (ON) in position - expect short circuit.
Test 1
With switch in its (OFF) out position - expect open circuit.
Test 2
With switch in its (ON) in position - expect short circuit.

Isolate as per TOPs P4
and refit as necessary