Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect 5 pin connector marked CN5 on the ignition PCB
Measurement:
Test 1:
Measure the resistance between the blue and brown wires at CN5.
Resistance will vary by fan but should be approximately 35-80 Ohms.
Test 2:
Measure the resistance between the brown wire at CN5
to a suitable earth point.
Resistance should be greater than 1M Ohm.
Measure the resistance between the blue and brown wires at CN5.
Resistance will vary by fan but should be approximately 35-80 Ohms.
Test 2:
Measure the resistance between the brown wire at CN5
to a suitable earth point.
Resistance should be greater than 1M Ohm.
Isolate as per TOPs P4
and refit as necessary