I have a 2001 9-5 SE, with v6. The alternator tested bad in the car. I replaced the diodes. It charged fine. The next day it quit again. I put in a new alternator. It charged fine. The next day it quit again. My question: Is there anything that can cause the alternator to go bad like that? Probably killing the diodes. The only thing electrically hooked to the alternator is the starter, the battery and the exciter circuit.