Hello, I have several trailers with 7-pin connectors. At the Ahk on the car have a 13-pin plug. So I use an adapter that is usually always in the socket on the car. For a few days the turn signal on the car no longer works and the lamp lights up in the dashboard with the wrench when the adapter is in the car and no trailer is connected. Before, the adapter has stuck at least 8000 km in the car without any problems. say what’s going on? mfg Friedel