Set Appliance State:
Set Multimeter to Resistance 
Isolate Mains Power to appliance as per TOPs P4
Disconnect potentiometer connector from PCB (Pink, Yellow and Violet wires)
Disconnect potentiometer connector from PCB (Pink, Yellow and Violet wires)
Measurement:
Test 1:
While measuring the resistance across the Pink and Yellow wires at the disconnected plug, turn the temperature control between maximum and minimum.
Resistance should vary between 4 ohms at maximum and 9kOhms at minimum.
Test 2:
While measuring the resistance across the Pink and Violet wires at the disconnected plug, turn the temperature control between maximum and minimum.
Resistance should vary between 9kOhms at maximum and 4ohms at minimum.
Replace connector after test.
While measuring the resistance across the Pink and Yellow wires at the disconnected plug, turn the temperature control between maximum and minimum.
Resistance should vary between 4 ohms at maximum and 9kOhms at minimum.
Test 2:
While measuring the resistance across the Pink and Violet wires at the disconnected plug, turn the temperature control between maximum and minimum.
Resistance should vary between 9kOhms at maximum and 4ohms at minimum.
Replace connector after test.
Isolate as per TOPs P4
and refit as necessary