Battery light in dash came on.What could that be?

[k's_silvia2.0]

I noticed yesterday that my battery light in my cluster came on but don't know why.
Nothing is wrong car starts up fine all lights work etc....If you think you
can diagnosse the problem lets get some input.Thanks for any help in advance.:wavey:
* I searched*

[azndoc]

My did that then the lights dimmed.

And my car died.

Booooooooo

[!Zar!]

Check your alternator. It could be going out.

[brokeAs240sx]

I believe that means your alternator is not working properly.

You can use a multimeter w/ the car off/on to verify this.

[k's_silvia2.0]

Its showing no sign of that.Anyways what would be some signs of it going bad?

[DRIFTING_SIL_EIGHTY]

1 sign is your dash lights kinda fade from dim to bright which is sometimes kinda hard to notice. best bet is to just pull the battery cable once the car is started. but then again if its barely dying then a multimeter would be your best friend.

[k's_silvia2.0]

^Hmm yea the light dont dim.So just disconnect the battery when the car is on?Anyone have a multireader I can borrow in socal?

[brokeAs240sx]

A multimeter can be had for about $10 u cheapskate ;). Also, I believe Kragen & Autozone let you borrow one for free (well, call first - only 1 of 3 I called let you borrow one, the others made you buy).

[DRIFTING_SIL_EIGHTY]

cant get no cheaper than this....
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90899

and i think it even came with batteries

[k's_silvia2.0]

A multimeter can be had for about $10 u cheapskate ;). Also, I believe Kragen & Autozone let you borrow one for free (well, call first - only 1 of 3 I called let you borrow one, the others made you buy).
HAHAHA I though they were a little more.:newbie:
cant get no cheaper than this....
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90899

and i think it even came with batteries
gonna pick one up.

[k's_silvia2.0]

Another quetion where would test the voltage?
I also have the Greddy turbo timer that has a volt meter.
What should voltage be?I have no stereo,hids,or anything that would draw extra power.Except my electric fans.

[PoorMans180SX]

Don't disconnect the battery when the car is running. The battery acts as a capacitor for the electronic system and you can blow fuses and such if you disconnect it while the car is running. Also, make sure you're using a decent digital Multi-meter. Don't use that analog bullcrap, it's worthless.

Also, your alternator could be having one of various problems. you really should check out the specs and do a voltage and amp test.

When the car is running it should be around 14.2 volts and about 12.4 when it's off. You can test voltage right at the battery.

Most digital multimeters can only handle 10amps, so I don't recommend testing alternator amperage output, unless you like blow multimeters.

[k's_silvia2.0]

^What numbers should I be expecting?

[PoorMans180SX]

edited, check it out.

[cruque]

Hello everybody. I don't know about you guys, but on my 91 in less then 2 years i've seen the battery light on twice. and it never fails, after that I check, BAD ALTERNATOR. The best way of cheking it is just to rev, you see the lights in the dash ,all lights get brighter that's if is alternator.

[k's_silvia2.0]

^Do you mean dimmer?

[usdm180sx]

Haha my alternator just died also. My battery light came on and my boost gauge and radio would lose power when I step on the brake.
The way I tested it was I disconnected the battery while the car was running and the motor just died. If the alternator was good the car would have kept running. Marco at sr20store replaced it no questions asked :D

[k's_silvia2.0]

^What that other dude said not to disconnect it whille its running.
Well ill listen to you Norm youve helped me out before.Thanks.
Also which do I disconnect Red or Black?

[usdm180sx]

Thanks Luis! I disconnected the red terminal. BTW did you get the boost situation all sorted out?

[k's_silvia2.0]

Well damn just got outta of Jack In The Box drive thru.Then all of a sudden my car dies?!?!?!?So I was for sure thinking the alternator just decided to die before I would enjoy my bag full of $1 goods.So I turn the switch....nothing no hazards,interior,cluster my volt stablizer was even off.So I call my buddy to try and Jump start it.Well I did a little inspection only to find my positive wire had come out of the crimp.I was so spyched that it wasnt the alternator.I was able to just shove it back far enough to get home.i grubed my food the had to take off the terminal and re-crimp it.My Greddy turbo timer has a volt meter and it reads 12.5/12.6 off 13.7/13.9running.I will probably just replace it for peace of mind.

[jdm_enthusiast]

Well damn just got outta of Jack In The Box drive thru.Then all of a sudden my car dies?!?!?!?So I was for sure thinking the alternator just decided to die before I would enjoy my bag full of $1 goods.So I turn the switch....nothing no hazards,interior,cluster my volt stablizer was even off.So I call my buddy to try and Jump start it.Well I did a little inspection only to find my positive wire had come out of the crimp.I was so spyched that it wasnt the alternator.I was able to just shove it back far enough to get home.i grubed my food the had to take off the terminal and re-crimp it.My Greddy turbo timer has a volt meter and it reads 12.5/12.6 off 13.7/13.9running.I will probably just replace it for peace of mind.yup exactly the same thing happen to my s14 before. 99.9% it's alternator. oh..... yea... about the disconnect battery terminal thing. it can't be done to every cars like what Turbo711 (http://www.zilvia.net/f/member.php?u=41183) said or else you might have to pay for the price. tho, i am not sure if you can do it to the 240s' but i wouldn't disconnect the terminal because it's easy just to check it with the multimeter.

[k's_silvia2.0]

^Yup gotta get on it bofore it leaves me stranded.

[AznDrftr.]

Yea better get that switched bro. Because, i had that with my DOHC at the time. Your alternator is holding no charge thus killing your battery instantly.

Hope you get that fixed man. You'll be going thru batteries like fat kids at mcdonalds.

[k's_silvia2.0]

^Well the battery is showing no signs of dying it has never just died.
Still though it should be replaced.

[mrmephistopheles]

Alll

Terrrr

Naaaayyy

Terrrrrrr

[MURPHY]

A multimeter can be had for about $10 u cheapskate ;).
damn i got raped by snapon haha

but word your charging systems messed up. load test time

[k's_silvia2.0]

Okay this morning started her right up and the battery light was off:)
Nothing dimmed theres a lot of fog out so I had my lights on.Gonna keep a close eye though.

[s13poop]

its best just to change the alternator rather than just holding it off

i had the same problem and it went away but of course those gremlins came back and i had to swap it out ASAP

usually dimming lights and a buzzing sound from the cluster are signs

my coupe sounded like a damn EZ bake oven cause of the buzzing!!

alternators are pretty cheap if you turn in your old one and really easy to swap out so make it a weekend project :bigok:

[k's_silvia2.0]

^Thanks Poop.Yea no buzzing yet but still I know better.
Ill make a it a weekday project.Too busy on the ends of the week.

[one_eighty_180]

get a decent multimeter at sears for $20. Check what its charging at, should be in the high 13's... low 14 volt range. That light coming off and on might be a loose connection or showing a sign of your alternator starting to take a poop... id say check for loose connections first

[s13silvia123]

mine's been on all these years i still have no clue. i even have a new alternator and battery as well since my last one went out. ever since i put my slim battery on its been like that.

[johngriff]

OP and s13silvia123:

Bad connections, test continuity of pos/neg wires and terminals, end to end to diagnose and fix.

[k's_silvia2.0]

Yup my positive harness came out of the crimp!?!?!?!So I was able to shove it back in and drive it home then fixed it.Now voltage reads 14.1-14.2.

[s13poop]

showing a sign of your alternator starting to take a poop.

someone say my name? :keke:

[k's_silvia2.0]

^That profile pic should be your sig.
Or was it a while ago?

[s13poop]

lol i would do it but my avatar is super small since im not premie anymore

i should be premie soon though

thatguy sent me that picture a while back and i thought it was hillarious

[k's_silvia2.0]

How long does it take for the alternator to go out if the battery lights on?
Or better what voltage will it show?

[roorr0]

How long does it take for the alternator to go out if the battery lights on?
Or better what voltage will it show?

mine took a day to crap out.

hey i heard with modifications you can use a KA Alternator as a replacement of the SR Alternator; true?

[k's_silvia2.0]

^Damn that suck they should have equip 240's with a "alternator going out alarm".

[randyjordan]

check if your belt flew off

[k's_silvia2.0]

check if your belt flew off

Well thats weird cause I dont wear belts:keke:
Nah all the belts are still there.

[g6civcx]

With all due respect to previous posters, you cannot use a small $30 multi-purpose multimeter to measure alternator output.

You need a voltmeter that can read up to 75-100 Amps. Take it to Autozone or your local garage and they should be able to measure the alternator output for you.

If you insist on using a digital multimeter, at least use an inductive current clamp so you don't blow the multimeter's internal fuse. Most of them are only rated for about .25-1A at most.

[mangoes]

very informative thread..

HI LUIS!!

[k's_silvia2.0]

very informative thread..

HI LUIS!!

HAHA unlike your's:keke:
Nah JP so what up?