Set Appliance State:
Set Multimeter to Resistance 
Isolate Mains Power to appliance as per TOPs P4
Disconnect Fan DC controller connector marked H3 on the main PCB
Disconnect Fan DC controller connector marked H3 on the main PCB
Measurement:
Test 1:
Measure resistance across the live (brown lead)
and neutral (blue lead) connection on the connector.
Expect Approx 44 Ohms.
Test 2:
Measure resistance across the live
(brown lead) and a suitable earth point.
Expected resistance O.L or greater than 1MOhm.
Measure resistance across the live (brown lead)
and neutral (blue lead) connection on the connector.
Expect Approx 44 Ohms.
Test 2:
Measure resistance across the live
(brown lead) and a suitable earth point.
Expected resistance O.L or greater than 1MOhm.
Isolate as per TOPs P4
and refit as necessary