Ive been noticing that when i role down my windows my fuel pump changes from a high pitch to a low pitch also if im in nutural and i rev my engine my head lights get brighter. the fuel pump chages pitch also when i turn on my head lights as well.

its nothing major but slight changes in the sound of the fuel pump and the headlights getting brighter. the car has never died on me or had a dead battery.

i think that my alternator might be getting week but wat other problems would i have if i had a weak alternator thanks

 

Tis normal. The problem is the already weak stock alternator that puts out 50-55 amps above 1k rpm. Alternators in general don't juice up much electricity below 1k.

I suggest taking your car to a local Autozone and have them do a load test. You can also upgrade to a GM 1-wire alternator and get more amps (75-150amps). I've posted info on ZDriver about that upgrade.

 

mine was like that, i changed it out with an alternator from an 87 maxima, 90 amps.
mainly because it was what i had on hand but it did fix alot of minor issues...