# Blown battery? Brake light and battery light malfunction?



## m_seats (May 21, 2004)

I started my car the other day and my lights went out and my car dogged down and then ran fine but it blew the bulbs in my headlights. my brake light and battery light came on went it did it. i looked under the hood and noticed my battery had the water coming out of it so i went to autozone and had my battery and alternator tested and found out that my alternator is good and my battery was bad so i replaced it. Then tonight i was driving and the brake light and battery light came on again and noticed that my subs on my stereo went off and then i just revved the car and the lights went off. I have a small stereo system and i have the halo projector headlights. What is causing these lights to come on? Do i have a short somewhere , cause i have no idea what it can be. Please give me advice on what to check and what it could be. Thanks!


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## nova73guy (Mar 30, 2004)

Had the exact same thing, minus the blown headlights, happen to me this past week. The alternator has taken a dump. When mine went, the battery and brake light came on, then the radio and lights started cutting off about 30 seconds before the engine started cutting out. It likely caused the battery to fail, so it's good you replaced it.

BTW: Don't drive any further until you get the alternator replaced or you could cause some serious damage to electronic components.


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## m_seats (May 21, 2004)

But at autozone i had my alternator tested and they said it was fine...they said it was putting out alot of amps but they didnt know how it was putting out 175 amps, but they said that was good. I just bypassed my a/c compressor pulley cause the barring was goin out and the light coming on has happened since then. I put the right belt on and it nice and tight. I just dont know....


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## nova73guy (Mar 30, 2004)

There's a short in the alternator that's causing it to WAY overcharge. That's why I don't trust dumba$$ autozone guys to test anything, because you don't necessarily have to know anything about cars to work there. Under even the heaviest load an 80amp alternator (I think that's what you have) should never put out 175. I'd get a second opinion (and I don't mean another parts store) from someone who's certified. It may cost a little, but it'll save you a lot of headaches and time later.

I'm not sure if overtightening the belt would cause this. I've seen tight belts ruin bearings before. It would have to be extremely tight, and even then the effect should be negligible. I do know bypassing the compressor didn't cause the problem. It's just coincidence.


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## m_seats (May 21, 2004)

Ill go to my mechanic...im sure it wont be too much...I may have sprayed some engine degreaser in it the other day so that may have cause the problem, i got some non conductive spray cleaner and sprayed it down yesterday and since then it hasnt done it. Hopefully, that will be the problem.


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## IanH (Feb 11, 2003)

nova73guy said:


> There's a short in the alternator that's causing it to WAY overcharge. That's why I don't trust dumba$$ autozone guys to test anything, because you don't necessarily have to know anything about cars to work there. Under even the heaviest load an 80amp alternator (I think that's what you have) should never put out 175. I'd get a second opinion (and I don't mean another parts store) from someone who's certified. It may cost a little, but it'll save you a lot of headaches and time later.


You are correct, alternators self limit current, and there is only a voltage regulator to prevent over charging the battery.
And yes there must be a serious problem for it to dump 175A under load. 
I agree that its got a short (probably in the stator winding.)
Yes is now busted !!!! To blow the headlamps the voltage regulator is blown as well.

Good Luck.....


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## nova73guy (Mar 30, 2004)

m_seats said:


> Ill go to my mechanic...im sure it wont be too much...I may have sprayed some engine degreaser in it the other day so that may have cause the problem, i got some non conductive spray cleaner and sprayed it down yesterday and since then it hasnt done it. Hopefully, that will be the problem.



Yes, degreaser will also do that. I've never tried the non-conductive cleaner on an alternator, I hope it works for you. Sorry if I sounded a little tense the other day, I just don't trust those guys to test anything. There's only one Autozone in the entire state of Texas I order parts from (and it's a half hour from the house) because it's the only one where I get what I order. As for testing, the mechanic is always best.

I wish you luck on the alternator. :thumbup:


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## B14Nismo (Oct 7, 2005)

I know for a fact its the alternator because when my alternator died the brake and battery light came on. When ever you see these lights come it's the engine telling you that your altenator is broke.


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## blackmaxima88 (Mar 20, 2005)

the brake and charge warning lights coming on simultaneously is a flaw nissan designed into their electrical system. they wanted a way to make the BRAKE light come on when you start your engine for a bulb check. so they wired it in parallel to the charge indicator light. so whenever the charge indicator is on, the BRAKE light is always on with it. it's a really stupid design.

these alternators (or at least the one in my B13 sentras) are only rated at 70 amps. if you were seeing 175, you've got a serious problem. since the charge indicator light is wired straight into the voltage regulator, and overcharging is a classic symptom, I'd venture to say your regulator is shot. you'll have to replace your alternator. the liquid you were seeing from the battery was battery acid, since it was being overcharged and the fluid inside was gassing and boiling. it was probably hot too, and the case was probably expanding. you'll probably need a new battery.


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## ditto0011 (Mar 2, 2005)

if the lights are going away at high rpms then its definetaly your alternator!!! had that same problem a while ago, don't listen to goddamn autozone, they told me that i had a bad battery and i bought a new 1 just to let the alternator drain that one too before i found out it was alternator! also i duno how easy it is on the sr20, but if you have a ga16, then good luck cuz changing that was a bitch! :cheers:


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## WiZzO (Jun 15, 2005)

lol i'm with ditto0011 on that, i get so frustrated changing my alternator on the ga16 that i end up taking out the radiator fans, coolant reservoir, and the top cooling hose to the radiator...i think there is something else too, cant think of it at the moment but yea definatley its your alternator


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## Navi00 (Sep 29, 2005)

I noticed back when I still had A/C in my B14 that whenever it was turned on, strange things like that would happen, also my engine would heatup and I'd loose A LOT of power.. I'm not sure if it's the same situation that you're in, but it sounds really simmilar.

Check all your fuses


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## nova73guy (Mar 30, 2004)

WiZzO said:


> lol i'm with ditto0011 on that, i get so frustrated changing my alternator on the ga16 that i end up taking out the radiator fans, coolant reservoir, and the top cooling hose to the radiator...i think there is something else too, cant think of it at the moment but yea definatley its your alternator


Actually, it's easier to unbolt the compressor and pull it down and to the side (don't remove it completely) to get the alternator out through the bottom. You still have to remove the fans and reservoir to get to all the bolts, but it's not that bad.


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