stupid electrical gremlins, please help

[matt4pl]

ok, so my battery gave out on friday. the car had been in the garage after it happened previously. i was driving and the air bag light would keep blinking and eventually stayd lit at which point the speedo stopped working and then soon after the car just died. no indicator lights or anything. i though it was the alternator, but that seems to be working fine, so then we assumed it was the battery. repalced it with an optima redtop. same thing happened. i had subs and a deck and all but thats all gone now. im gonna check the grounds tomorrow but i dont think thats it. any idea where to start or what to check? im thinking its gotta be a powe drain somewhere. where its at is gonna be fun to find...

[navysnail]

how did you go about testing the alternator?

[matt4pl]

we hooked up a multimeter and measured the volatage between the two battery terminals with the car running

[PMan_S13]

I would seriously consider looking at the alternator again, if it were me.

Very similar thing happened on a friends accord with subs/amp. The stereo drew so much power it exhausted the alternator.

If you're mecahnically inclinded, it only takes maybe a half hour to take the alternator completely off the motor. If you take it to autozone, advance auto, napa, etc. they can do a detailed diagnosis on its performance. It's a little more clear than the old voltometer =)

BTW, if the car is running, there HAS to be a voltage across the battery, otherwise you can't spark, use fuel injection, use timing, tach, speedo, etc. You can have a bad alternator with a running vehicle... it just means it doesn't recharge as much as the car is using.. so it will drain the battery and then be dead.

Hope that helps somewhat.. good luck

[matt4pl]

oh and one more thing. i found that the wires goign to the MAF were rubbing on the PS pulley. im not sure, but could that be a source of a short that could cause a battery to die within a day?

[s13sr20chris]

sounds very much like an alternator problem to me too. if you put an alternator on it DONT get one from autozone or advance. i have see too many of them last 1 month and fail. also, nissan alternators cannot be properly tested off the car. if you buy an alternator get a nissan alt from dealer or junkyard. if you must have aftermarket get a better one from napa or something.

[matt4pl]

so i put in an new alternator. turned the car on (jump start). car runs fine, turned the lights on, the air on, the half installed speakers, etc. car runs fine although the airbag light kept blinking. turned the car off... battery feels like is hasnt been charged at all. i also notice a slight smell of something warming up too. dunno about that cause my nose was running from teh cold. im so stuck...

[metalsyth]

i found that the wires goign to the MAF were rubbing on the PS pulley.

I may be wrong but I think if the wire going to the MAF and rubbing on the PS pulley has wore through the plastic it could cause a short to ground and if I remember correctly can cause some of the problems and as for the altenator you can test it by having the running and disconnect the positive battery wire. If the car shuts off then the alternator is shot and if the does not shut off then the alternator is working but it may still need to be checked out.

As for the airbag light blinking if I remember this correctly is a switch or a sensor that had become defective and it can create a parasitic draw and kill the battery.

Please forgive me if any of this info is incorrect I am going to school to become and a Mechanic and I am trying to help diagnose with what I have heard. If any of this info is wrong please correct me.

[matt4pl]

hey, thanks bro, dont worry, any info is good info unless it comes your ur a$$, so thanks, i'll check some things out tomorrow