A contact plate 10 is inserted between the flat conductor 3 and the electrical conductor 1. This contact plate 10 is tiered, i.e. it has an area of reduced thickness corresponding to the thickness of the flat conductor 3, thereby creating a large-surface support for the flat conductor 3 and enabling both parts to be securely interconnected by, for example, an electrical bonding process such as ultrasonic welding. The same arrangement may be used for the connection between the electrical conductor 1 and the contact plate 10. Here the electrical conductor 1 is flattened at an exposed end 11 in such a way that a large-surface support is formed on the contact plate 10. It is also possible to use an electrical connecting method such as ultrasonic welding.

To facilitate subsequent overmolding of the junction between the conductor 1 and the contact element 3, an adapter 5 made of polypropylene (PP) is slid over the electrical conductor 1 and its PVC or silicone insulation 2 and attached in an end portion 12 of the PVC or silicone insulation. Applying an overmold 7 to the junction, typically by an injection-molding process, yields a seal not only of the exposed ends 11 of the conductor 1, the contact plate 10 and an exposed portion 13 of the contact element 3, but also of portions of the adapter 5 and the jacket 4 of the flat conductor 3.