Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove the 4 wire connector from the fan assembly

Measurement:

Test 1:
Measure the resistance between each of the fan terminals
listed below on the 5 pin connector on the fan assembly.
Resistances should conform approximately to the table below:
Test point 1Test point 2Resistance
Terminal 1Terminal 216.8 kohms
Terminal 2Terminal 440 kohms
Terminal 4Terminal 53.6 Mohm or greater
Terminal 1Terminal 424 kohms

Test 2:
Measure the resistance between each of the terminals 1, 2, 3 and 4 to earth.
Expect a resistance greater than 1 Mohm.
Are the resistances measured as expected?