I think my alternator is shot on my 01 dc2 gsr. my car will idle at 2-400rpm, engine wont die tho, and my digital voltage readout shows that its running at 12.4 volts. seems to happen only at idle. and when im at idle, ill rev to 4k rpm, then it will shoot back up to 14v and then ill let go on the throttle it will go back to 12 volts. problem doesent seem to occur when im driving since it shows 14v. this happens maybe every 1/3 times i stop. the other times i idle at 600rpm showing 14v. problem is slowly getting worse. is my alternator shot? a direct replacement of my alternator fix the problem?

 

Sounds like more of an idle problem than the alternator.

Is your battery dying as a result of this, because it sounds normal to me?

 

my battery hasnt died once yet. and ignition crank seems to be pretty consistent and works well. original battery that came with the car when i bought it 4 yrs ago.

 

your alternator is fine. like shmoo said, you might have an idle problemo.

 

my car never went down to 12v like that unless i was pounding my system. The car should hold a charge of 14.4v continuously in idle or driving. is the idle issue causing this?

 

Voltage shouldn't drop to 12v at idle, unless you have a lot of electrical accessories running. Are your battery cable connections tight and free of corrosion?

 

if your alternator was bad your battery would have gone too, especially since you have a system

 

i do have two amps running. even w/ no bumping this is still an issue. not sure on the battery connectors but ill check.

update:

so i disconnected both amps and the car seems to be holding 14.4v. even rolling to a stop in neutral my idle holds at 800rmp and then as soon as i stop it kicks down to 500-600rpm @ 14.4v

although my car is idleing lower than usual, the voltage drop and the shitty idle at 200rpm (my engine starts to shake at this point) seems to be when my amps are connected. hmmmm...

 

i was able to make my amps sweat and my car was able to hold its charge no problem.