Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Remove the 4 wire harness from the fan assembly and the
main harness at the inline connector
main harness at the inline connector
Measurement:
Measure the resistance of each of the wires in the harness from the fan connector to the harness connector.
Expect continuity / zero resistance on each wire.
Also visually inspect the harness.
Are the resistances on each wire as expected and is the harness in good condition?
Expect continuity / zero resistance on each wire.
Also visually inspect the harness.
Are the resistances on each wire as expected and is the harness in good condition?
Isolate as per TOPs P4
and refit as necessary