Overcharging - alternator suggestions?
If that is your alt it is not internally regulated.
Your photos seem to indicate it's not the same akt as the number your posted.
Based on your description it sounds and looks like it has one field terminal internally grounded and you are feeding 12v to the other field wire causing a full field situation.
Red arrow shows no terminal on FLD 2
Yellow arrow shows lock washer making a ground to the field terminal.
Green FLD 1 terminal has a connector on it, where does it go to?
If that is your alt it is not internally regulated.
Your photos seem to indicate it's not the same akt as the number your posted.
Based on your description it sounds and looks like it has one field terminal internally grounded and you are feeding 12v to the other field wire causing a full field situation.
Red arrow shows no terminal on FLD 2
Yellow arrow shows lock washer making a ground to the field terminal.
Green FLD 1 terminal has a connector on it, where does it go to?