Set Appliance State:

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

Measurement:

Test 1:
Measure the resistance between pin 1 (red) and pin 3 (blue) on the fan connector.
Expected resistance between 110 - 130 Ohms.
Test 2:
Measure the resistance between each of the wires at the disconnected connector to Earth in turn.
Expected resistance greater than 1 MOhm.
Note.
A reading of O.L on test 2 is acceptable as this is greater than 1 MOhm.