Hmm, sounds logic, but in my case the fuse, the guy is pointing on, was two time blown.
One time when I swaped my positiv and negative poles on my battery and another time, when I worked on my radio, without any shortcut. That leads into not working gauges and i had a christmas tree of warning lights, like ABS, traction control, battery warning, engine lamp and so on.
Probably the picture I found in the Internet of the fuse box is different to the fuse box of my car, because it was surely not the trailer electric fuse.
Now it's in the middle of the night and it's raining, but tomorrow I will look on my car, what fuse it was, which was blown.