Trailer coupling Wiring W463 BJ 2002

Hi Together, I would like to upgrade an AHK on my W463 from 2002. I organized the “hardware” so far. What I still lack is the cable harness. I found a control unit in the wheel box at the rear of the driver’s side “Supplier-Connector” 0295456732(03). Is there original or accessories cable strands that can be plugged in there? I couldn’t get any further via EPC, the part number for cables are NML… the search in the forum did not bring any results, since it is always about other execution I really want to do without frigging, so put cables around everywhere and wire everything myself with Stromdueven… Thank you for tips