An adapter received in an opening of a partition wall of a vehicle door connects a cable plug of a cable harness to a module plug of a door control module. The adapter includes a mount for the module plug, a mount for the cable plug, and an abutment face providing a seal at the partition wall. The adapter further includes a latching tab. When the adapter is inserted into the opening, the latching tab flexes outwardly, securing the adapter to the partition wall. The module plug and the cable plug can be inserted into or removed from the adapter without affecting the sealing between the wet area and the dry area of the vehicle door.