well i posted on here about this before but i have some more questions. i have a whinning noise coming from my motor and it goes up and down with the rpms. i was told it may be my alternator but i got it checked at autozone and they said it was charging at around 13.3 amps and normal was 13.5 to 14 and that it seemed to be good. the guy said it may be a bad diode or the begining of the alternator going bad. this has been going on for about a month but i dont seem to be having any problems charging my battery and i have a system that i regulary crank up. any body got any ideas as to what this could be?

 

13.3 is an ok #, although its below 14.1-14.7. My car started to have the VOLT and BRAKE light coming on at 11.6 and finally my alternator quit on me. Mine whined also, and it got louder the weaker it got.

 

That does sound like an alternator problem. I replaced one on a Saturn that did that too. It worked for 2 months before it finally went. If you can actually hear the whine from the alternator I would just replace it and be done with it.

 

Had the same noise. TOok it to the dealer and they changed out the alternator due to warranty. No noise since last year.