battery indicator light comes on.

[htcsilent89]

hey fellow car lovers!

i currently own a stock ka24de s13.

first time being on this forum but its been highly recommended from my roommate as a great place to come with for any problems i may have.
in the last few weeks Ive been having an issue with my abs pump to currently staying on. found out i had a leak in my master cylinder and got that fixed. but when i got my car back from the mechanic i noticed that my battery indicator light comes on after 5-10 minutes of driving. it goes off when rev/depress gas pedal. Ive read that this is my alternator not creating a charge and im just running off of battery power.

i took a multimeter and tested the battery while my car was off. it created just under 13 volts. car on and running in idle creates 15volts. wouldn't a spike in voltage like this generally mean that my charging system is working?

Ive also noticed a small buzzing sound coming from my dashboard whenever my car idles and the battery indicator light does come on.

if both my alt and battery is fine, what would i check next to fix this? would a simple restart of my ecu fix it?

thanks, i hope i get help sooner then later.

[S-chassis life]

when you drive it at night when you have your lights and everything on have you noticed a sight change in dimming from your dash or headlights ? and suddenly goes back to normal ? if so it is your alternator and its only a matter of time when it gives out completely.

Now im just saying this cause it has already happen to me twice maybe it might not be the issue with you but it almost sounds like the same problems i had. brake light come on with the battery light and then it goes off at first. then after awhile in a matter of a week or so depending in how much you drive your car it starts getting worse. your car might turnoff at a stop light and you might have to rev it up so is can keep running, but if thats happening your alternator is whats causing the issue, it slowly starts to get weak to the point where it wont even charge the system anymore, search for an alternator around your area, if you can find one for cheap get it. and if its at a auto store make sure you get a lifetime warranty i was able to get mine for 90 bucks with a lifetime warranty from Carquest autoparts, i have already changed my twice due to having a amp and sub witch really works out your alternator trying to keep that wattage up on the amp depending how big of a system you have. i just have one 10 with a 500w rms amp so it does work the alternator a bit, but with that lifetime im not too worried about it.