Just got a call from the Shop. Seems like it's the positive cable that goes to the fusebox. They say BMW made a recall for this.
I did found a link
https://bit.ly/2GhjAVv
It fits what my car did to a T but they say it only affect
X1 Series vehicles produced July 3, 2013 – July 17, 2013...
Mines is a 2011 production. Weird. The car got exactly all the problems described in this PDF.