Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance

Measurement:

Disconnect connector X3 from the PCB
Test 1: Measure the resistance between the fan neutral (marked 13.5) on X4 and each fan connector (marked 13.1, 13.2, 13.3 and 13.4) on X3 in turn.
Expect greater than 1M Ohm on each test.
Test 2: Measure the resistance between each fan connector (marked 13.1, 13.2, 13.3 and 13.4) on X3 and a suitable earth point.
Expect greater than 1M Ohm on each test.
Test 3:
Disconnect connector X4 from the PCB.
Measure the resistance between the fan neutral (marked 13.5)
on X4 and a suitable earth point.
Expect greater than 1M Ohm.
Note:
The red wire on X3 marked 10.1 is for the spark generator
and does not need to be checked for this test.