Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Measurement:
Disconnect the High/Low Switch White and High/Low Switch Purple wires at their flying lead spade connections.
With the Switch in the High position measure the resistance across the White and the Purple spade terminals from the Switch.
With the Switch in the High position measure the resistance across the White and the Purple spade terminals from the Switch.
Isolate as per TOPs P4
and refit as necessary