anyone know anything about car electric

[matt6669]

well boys im calling all of you
does anyone know anything about electrical systems in cars.
i have my wrx and i've been getting dead batteries for hte longest time, i started to figure it out why im getting dead batteries but im sunk in the water and can't go any farther as my knowledge is very limited.
if anyone could give me a hand that would be awesome
Matt

[sentinal02]

dead battery from like sitting over night you mean? or like you do a lot of quick trips and your batt doesn't take a charge? the first one is likely a parasitic draw somewhere. get an ammeter that will read DC amps and put it in series between the neg cable and ground. see what it says. you shouldn't be pulling more that 50 mA or so. anything more than that means you've got something that's drawing power even when the engine is off. once you can see the draw, you can start pulling fuses one at a time to see which one cuts off the draw. then you can look at a wiring schematic and see what circuits branch of that fuse so you know where to start looking for your short. the second situation i mentioned is likely the alternator not putting out what it should.

[matt6669]

whelp its deffs the first one
if you want to read up on it go here
http://forums.nasioc.com/forums/showthread.php?p=10135576#post10135576
go there and it explains everything that is happening hahahahahha

Matt

[speedracer983]

Do you have a big audio amp ? ( aftermarket system ) ... if it's not turning off it will have enough draw to kill a battery over night ?????

[NYWheeler]

Its real hard to diag an electrical problem without seeing the car. The 23 or whatever ma you were getting is that with everything plugged in and as it would be if you are driving? If so thats a normal reading.
you shouldn't be pulling more that 50 mA or so.
this was correct for many years but with the amount of electronics in today's cars most manufacturs consider 90ma to be acceptable. most new cars less than 1/10th of an amp is ok.

[matt6669]

no aftermarket radio just the stock headunit thats it
and that was with everyone plugged in but no key turned on or anything

Matt

ps its deffs not the alternator i had a dead battery last night let it run for ike 45 min and when it was running it was 14 and when i turned it off it was 13 volts so its deffs getting a charge i deffinitely have a short somewhere

[MYGOODNESS]

Matt,

I'm not sure if you ruled out your battery but I had a similar problem with my Durango.
Current test did not show a problem but the truck would be dead if i let it sit 1-2 days. Turns out the battery was the problem.

The way i found it was after a long ride(battery was charged) i pulled a battery cable and parked the truck. Monday morning a connected the cables and guess what the battery was dead.

BTW the battery was less then 3 months old.

If your not seeing a strong current draw at rest give this a try.

Gene