Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Disconnect fan connector at fan

Measurement:

Test 1: With the black probe on terminal 4 for each test measure resistance across the fan terminals as listed in the table below.
Resistance should conform approximately to the table below:
TerminalsResistance
4 - 1Greater than 1 MOhms
4 - 2Greater than 1 MOhms
4 - 3Greater than 1 MOhms
4 - 5Greater than 1 MOhms

Test 2: Measure the resistance between each of the terminals on the fan to suitable earth.
Expect 1Mohm or greater on each test.
(OL is acceptable because it is greater than 1Mohm)
Are the resistances measured as expected?