That alternator uses a "sense" wire so it knows what voltage the battery is at. Where did you connect that "sense" wire? Do you have a bypass wire directly from the alt to the battery? If you connected the "sense wire" to the alternators battery + lug you really need to do the amp gauge bypass and have a 10 gauge or larger wire run from the alternator to the battery.(or starter relay) If there is a lot of voltage drop in the wiring and the + stud on the alternator is showing low voltage, then the alternator is going to think the battery is low and increase the output. This is the downside to this style alternator.