The car is a 2013 Seat Mii with start/stop functionality.
The alternator is faulty as the output (measured at the alternator on an oscilloscope after the regulator) fluctuates between 3V and 14.5V in a random pattern. It should stay constant at 14.5V.
I've killed my battery due to undercharging through several weeks.
Is it the regulator (built into the alternator) or the alternator itself which is faulty ? Is it repairable ?
The alternator is a 110A BOSCH item with part number 04C 903 023D