I think that all the power lines connect to pin nr4 on the fuse box, one of the 2 pins of the fuse. So, i will check later for a short circuit between pin 4 and ground. I believe I am going to find a short circuit there, but still I will not know which valve/sensor is faulty. There must be a "junction box" somewhere, that all the power lines meet, but I can't find it.