Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect right connector from PCB (16-31)
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
With the pump running and the microswitch spindle fully extended measure the resistance between the violet wires (18 & 19) at the disconnected plug.
Resistance should be short circuit (zero resistance).
Resistance should be short circuit (zero resistance).
Isolate as per TOPs P4
and refit as necessary