Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect connector X23 from the PCB
Measurement:
Test 1: Measure the resistance on the harness connections as below.
The resistance should conform approximately to the table below:
Test 2: Measure the Resistance between each of the following wires to earth:
The resistance should conform approximately to the table below:
| Leads | Resistance | Blue (1) - Brown (2) | 34kOhms |
| Brown (2) - Black (4) | 16kOhms |
| Blue (1) - Black (4) | 50kOhms |
Test 2: Measure the Resistance between each of the following wires to earth:
| Leads | Resistance in Ohms | Blue (1) | Open Circuit |
| Brown (2) | Open Circuit |
| Green (3) | Open Circuit |
| Black (4) | Open Circuit |
Isolate as per TOPs P4
and refit as necessary