Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove the harness connection from the diverter motor

Observation:

Measure the resistance of each wire of the diverter motor harness.
The connector at X16 is numbered 1-5 from left to right.
The plug to the diverter motor has the corresponding positions illustrated.