Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Remove the 4 wire connector from the fan assembly
Remove connector X20 from the PCB
Remove connector X20 from the PCB
Measurement:
Measure the resistance across each of the wires running from the 4 wire fan connector to the corresponding wire on X20, pins 3, 4, 15 and 16. For example pin 3 (black wire) on connector X20 to the black wire on the fan 4 wire connector.
Expect continuity / zero resistance on each wire.
Also visually inspect the condition of the harness.
Are the resistances measured as expected and is the harness in good condition?
Expect continuity / zero resistance on each wire.
Also visually inspect the condition of the harness.
Are the resistances measured as expected and is the harness in good condition?
Isolate as per TOPs P4
and refit as necessary