Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove fan power connector to fan assembly

Measurement:

Measure the resistance (continuity) across the fan power harness leads.
Connections are;
Expected resistance is continuity (zero resistance).
Note.
1. PCB connector numbers can be found on the board.
2. Ensure a good connection is made or misdiagnosis will occur.