Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Remove Condense Trap
Disconnect Pump DC connection from pump as shown on the right.

Measurement:

Check the continuity of each of the wires in the harness as below
White to Terminal 3
Black to Terminal 2
Purple to Terminal 1
Expect zero resistance/continuity on each test.
Also inspect the harness visually for signs of damage.
Note:
Before reassembly check the integrity of all disturbed gaskets and seals and replace as necessary.