Good evening.
I have a 1998 Ford Explorer V6 with 172k miles. The original alternator failed in November, and I replaced it with a "premium" rebuilt alternator from NAPA. (The "premium" designation means that they install a new rectifier instead of a "good used" recitifier. I considered this an intelligence test.) This alternator failed a week ago. I returned it and they gave me another one.
What I am wondering is, could there be some other issue with the electricals that is causing alternators to fail? Certainly it is no surprise that the _original_ failed with nearly 170k miles on it, and it is also possible that the first rebuild was faulty. But now I am worried that a few thousand miles from now I will encounter yet another failed alternator, perhaps when I'm up in the mountains rather than a few blocks from home. I want to make sure that there is not something else wrong that is causing alternators to fail.
I checked the voltage drops from the BAT connection to the battery (+) terminal, and from the alternator case to the battery (-) terminal. The drops were
0.08v and 0.02v respectively. Those are acceptable I believe. Is there anything else I should be checking for?
Thanks
-Mark