alternator question

[oldexplor]

Hey i have a 95 explorer and i had to get a new battery the other day and now the new one wont charge because the alternator is goin bad.. so now i need to be lookin for a new alternator..what do you guess suggest? i have an amp hooked up to my battery right now so i might need a little bit more power from the alternator..i was looking at them on the advance auto parts site and i was probably goin to buy one from there since they seemed pretty cheap..but will somebody please help me on what kind of alternator i need? thanks

 

[BrooklynBay]

If you have a lot of power accessories that pull a lot of amps, you might want to get a 200 amp alternator. They are not cheap. Those big 1 Farad capacitors, and a yellow top Optima battery would also be good.

 

[BrooklynBay]

Aldive has an alternator pulley listed in one of his threads that is a smaller diameter than the stock version. It is about $40. Since it is smaller, the alternator will spin faster than normal at idle, and any other time. It will maintain a higher current level at idle because it is spinning faster. If it spins faster all of the time, it will cause more friction on the bearings, and brushes, but won't make much of a difference on the longevity of it. It's only spinning a little faster.

 

[aldive]

Take a look at http://www.explorerforum.com/forums/showthread.php?t=154990&highlight=overdrive+alternator

 

[BrooklynBay]

Thanks for posting that link Al. Here is a side by side comparison of both of those pullies:

The left one is the stock version, and the one on the right is the smaller pulley from Underdog.

 

[Green98XLT]

Stock Alternator on your truck was under-rated at 130amps. It will actually produce around 150A. If you only have one amp then I'd say a stocker would be fine for you. The over drive pulley is a good idea too but not really needed unless you are running underdriven crank pulleys and such..

Have you verified that it is your alternator that is failing? Have you done any voltage drop testing? Are your battery cables all in top shape?

I'd get a DVOM and start looking around, you might find that you don't need a new alternator afterall.

 

[oldexplor]

hey thanks for the quick and good replies..yeah it was the alternator we got it fixed and it seems to be workin for now alright

 

[BrooklynBay]

Thanks for letting us know. Did you get the 130 amp alternator?