Battery keeps dying (probably parasitic drain)

onestla

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So i just bought an 1994 sn95 GT. Everything runs fine with it except my battery keeps dying overnight. Its a brand new battery, i tested it and the alternator (12v and 14v). i removed the radio fuse and the Radio amplifier, Subwoofer amplifier fuse and i also unplugged the driver seat electric controls but my battery is still dead. I don't know if someone had the same issues as me, i read some other posts and no one seems to have the same issue at least for a long time everyone seems to fix them fast so i would like some answers. Thanks!
 
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onestla

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what alarms ? the only one i have is when i open the door or when the key is in, its the same alarm for both.
 

RAU03MACH

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some of the factory ones do rob power
you have a draw somewhere then
check the ignition system over
 

RAU03MACH

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when trouble shooting there is no fast answer
this will make a mechanic out of you if you fix it
trouble shooting electrical problems are nightmares sometimes
 

cobrajeff96

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Make sure the map lamps are switched off, easy thing to overlook.
 

RAU03MACH

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gotta be something easy
door jam switch
trunk switch for light
key switch
light switch
 

ttocs

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did it have a mach system? The front amp is probably still under the radio plugged in and drawing power as they are known to do.

If you want to narrow down which circuit has the draw you will need to disconnect the battery, set a multimeter to current and then put it between the battery and ground. At that point the meter will show a reading that should be as close to 0 as possible, but anything over that is the current drain. Now to figure out what circuit, start pulling fuses one at a time and eventually you will pull one and the current reading on the meter will drop. At that point you know what circuit has the draw and you can narrow it down further.

As they said it could be as simple as the light in your glove box or trunk staying on, or the amp.
 
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onestla

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It does have a Mach system, I thought removing the subwoofer fuse would kill it as well. I’ll try finding where the cables are and removing them directly from the Mach system. It seems everyone has the same issues with the Mach system. Also I don’t have a trunk light not any other light that stays open, I even checked the glove box one and it turns off when I close it. How would putting the multimeter in between the battery and the ground help me find the drain ? I’m really new in electricity issues :(.
 

ttocs

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it shows the current that is being drawn from the battery where voltage will not work as well because it is so small. By disconnecting the battery and putting the meter in between the two all the current has to go through it. So when you first hook it up, it will show how much the drain is. Then by pulling one fuse at a time, you disconnect one circuit at a time and sooner or later you will see the current on the meter drop significantly. At that point you know what circuit is drawing the current and we can narrow it down from there.

The front amp has nothing to do with the subs it is more of a cross over/amp that divides the signal. You can disconnect it and see if it stops it.
 
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onestla

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Thanks for the response but i realized today that my batterie doesn't get drained. My batterie charger was faulty and it kept telling me that it was discharged when it wasn't (i checked it with my multimeter and its at 12.8V after letting it rest for 24h). I do still have issues starting the car sometimes but I'm pretty sure its either my starter or my ignition switch that has issues so I'll do another post in the engine section for tips on how to check my starter module. Thanks again for the help!
 

ttocs

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Does it only have issues starting if it sits for a while? if your car has issues starting after it sits for a few days it could be a slow power drain, a weak fuel pump or leak in the lines. I am not sure how the starter or switch would matter if it is time based

But then also realize the test I gave takes maybe 10 mins. You undo one bolt put the meter in and start pulling fuses till you have pulled them all one at a time.
 

cobrajeff96

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So, now does this change the entire diagnosis? Seems the battery doesn't fall flat anymore even after long hours sitting. Seems like it's just a cranking/starting issue?

Easiest thing to check first is ground connections and the connections right on the starter. It goes without saying that all electrical connections need to be tight and rust free whether they are hot or ground.
 
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onestla

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Yeah I think it just changes the whole problem because my battery doesn’t drain, at least it didn’t when I checked it two days ago. I’ll check it again tomorrow night and see if it was drained or not, but I’m mostly sure it’s my starter because I tried starting the car and it didn’t want to and my father tried not even 5 minutes later and she started (apparently I’m not man enough xD)
 

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