bad alt?

[afmafia]

hi guys i been having problems with my battery dying when i go to start it . it seems when i get in my car all my dash lights turn on fine then as soon as i start to crank it over my lights dim and theres no juice . if i put a battery charger to my battery to jump it it starts right up with no problem . so im thinking i have a bad alt since i tested my batery with a voltage meter and it read 12.10 volts. what do u guys think ?? also what usdm alt can i use on an s13 blacktop sr20det rwd any info is appreshated .

[Rosco]

Before you order an alternator, get your battery tested at advance-auto. As far as I know the only parts you need from Japan are alternator, starter and water pump. So you'll have order it up.

[Silvia007]

KA-DE alt works. I managed to get a 97 Quest alt to fit with some fabbing but for an extra 30 amps. Not sure if it's worth it. The results however kicks butt.

[afmafia]

so the ka24de one work but what year ka24de 93 ka24de is 80 amp 4 grove belt 98 ka24de is 100 amp 4 grove 3 o clock what one do i use???????

[Blown240sx]

WOAH WOAH WOAH before you go spend money and time on this lets get some stuff cleared up.

A. Does the car run fine after you jump start it?B. Or does the car start then die after a min and wont start again cause th batt. is dead?

If you answer A yes and B no. Then your Alt. is fine the battery is bad. Trust me been there done that.The reason for this is because while running the car does not use the battery to power itself unless you have something pulling from the battery, like stereo stuff.

If you answer A no and B yes then your Alt is bad and time for a new one. KA24DE works fine just need to round out some of the bolt holes.

Or you could have a slowly dieing Alt that provides enough juice while running but not enough to keep the batt charged. I would get the car running take it to a car store have the whole thing tested batt and alt.

Or a self test you can do is leave h car sitting for a while and then test the batt voltage. When my batt was going bad it would loose power while sitting for periods of time. It got to the point that at startup I had 9 volts.

[afmafia]

its like ill jump my car and it will start i try to start my car 5 min later my battery is dead . i think its a bad alt well see today

[Blown240sx]

BUT when you jump it the car runs fine?Dude Im serious sounds like your battery is dieing. Did you check the voltage on the battery before trying to start it or right after you turned the car off?

[xero1]

is the battery light on the dash? what the battery voltage when the car is running?

[afmafia]

checked volts on battery its runing at 12 voltschecked the alt its running at 14 voltscheck the batterys cold cranking amps 310 so its a bad battery

[xero1]

with the car running the battery volt should be at least 13.v, double check you meter

[afmafia]

12.2 was with the car off

[DRIFTINIZ]

would an alternator thats going bad possibly make a whining sound when you start up the motor from a cold start. reason i think its the alternator is because whenever i rev up when its making the whining sound my lights get brighter and then dim back down again. so maybe my pulley or bearing is going out and not giving the engine enough juice?? the whine sounds like when your power steering goes out.....

[180sxmonster]

try the old school way....with the car started...disconnect one of the terminal on the battery...if the car dies,the alt is bad....if it stays on after removed, its good.....a good alt should run 13.5 - 14.5 any where below or above is bad....

oh yeah, your alt should put out 100 amps under load test.