Battery draining?! Alternator/battery/starter?? Help

civic939

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I am having a problem with my 96 civic dx with 104K miles. The battery seems to drain after half hour of the car being shut off. And then sometimes it can sit over night and start just fine. Outside temp has nothing to do with it. I have checked all fuses for draw and only found the radio backup and interior lights to have a draw (radio i understand but the int lights [doors were closed]??) this is only a small amount of draw and shouldn't kill the battery that fast. I even tried pulling the radio and int lights fuses for a day just to make sure. My alternator is charging just fine. I'm thinking possibly a bad reg in the alternator causing it to draw while car is shut off. Except the alternator doesn't get warm like it should when the car is off if that is the problem. Jumping the car starts it like it has brand new everything. Push starting has been my way of getting it going the past few days and that works good but is a pain in the ass. The car is completely stock and i have no aftermarket stereo or amp. No power windows/locks/security or antena. I've checked for lights being left on, buzzing noises, ticking. The battery is only about a year old. I would get a new alternator, starter, and battery to rule them out but i'd hate to spend the money and have it be something else. And end up messing up my new battery. If anyone has a similar problem AND a solution please fill me in. One other thing that may or may not mean anything is that right before the problem started my SRS light came on. I didn't hit anything. One day it came on and i shut the car off and restarted it and it was off. Then the next time it was on and it has been coming on when i start the car since. Please let me know if anyone has any ideas or tips that i haven't tried yet.

Thanks.
 

stateofjustin

New Member
You need to take a few steps back and re-do your troubleshooting.

Half of what you posted makes no sense, half of it does. Most of the stuff that makes sense you said you ruled out somehow.

Neither the alternator or starter should draw current when the car is off, unless you are turning the key to start the car.. in which case the starter would draw current first to the engaging solenoid, then the starter motor to turn the engine.
You would have to have a direct short, which for those components would equal blown fuses.

Is your car completely stock? does it have an alarm? a stereo system? How old is the battery?

FYI, an interior light will kill your battery overnight. Our batteries are tiny.

You may have an intermittent short to ground. The only other way to kill a battery in a half hour is to crank the engine continuously until the battery is dead. Go over to Kragen or AutoZone or O'Rileys or whatever parts store is around and have them test your battery... if bad replace. Put in the old or new battery, and have them use the alternator tester to make sure you are getting 14.4 and proper diode ripple. If bad, replace. If both are good, disconnect your fuses for non-critical functions and see if you're good. If not, start going through those one by one. If you're good, start re-adding fuses one at a time until you get the problem back. That may help you narrow it down a bit.

It could just be an intermittent short in the battery though, when then test it have them jiggle it around a bit (and check the water level).
 


civic939

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I really don't mean to be a d**k but did you read any of my post?

YOUR POST - "Neither the alternator or starter should draw current when the car is off, unless you are turning the key to start the car.."

MY PREVIOUS POST - "There is a regulator diode in the alternator that prevents the battery from back feeding into the alternator. if it goes bad then it will drain the battery when the car is off."

YOUR POST - "Is your car completely stock? does it have an alarm? a stereo system? How old is the battery?"

MY PREVIOUS POST - "The car is completely stock and i have no aftermarket stereo or amp. No power windows/locks/security or antena." "The battery is only about a year old"


YOUR POST - "FYI, an interior light will kill your battery overnight. Our batteries are tiny."

MY PREVIOUS POST - " The battery seems to drain after half hour of the car being shut off."

YOUR POST - "disconnect your fuses for non-critical functions and see if you're good. If not, start going through those one by one. If you're good, start re-adding fuses one at a time until you get the problem back. That may help you narrow it down a bit."

MY PREVIOUS POST - "I have checked all fuses for draw"


USEFUL INFO FROM YOUR POST

"It could just be an intermittent short in the battery though, when then test it have them jiggle it around a bit (and check the water level). "

-jiggling the wires has no effect

-fluid level in batter is at normal
 

stateofjustin

New Member
USEFUL INFO FROM YOUR POST

"It could just be an intermittent short in the battery though, when then test it have them jiggle it around a bit (and check the water level). "

-jiggling the wires has no effect

-fluid level in batter is at normal
Jiggling the battery, not the wires. If a plate is loose it may make contact during a test and show up (as it might while driving or when you park), also conductive debris in the battery from time/vibration/or defect can cause intermittent issues. The age of your battery lessens the odds of a defect, but does not rule out anything by itself.

I'm glad you checked all the fuses and such, but you can't check them all constantly. Since the information you provided clearly states the problem is intermittent, a static reading of things is of fairly limited use to you.
Since it can go until the next morning and start fine or die in a half hour, the odds of you finding it on your first go round are pretty slim. Especially if you have not noted on paper all the conditions every time to try and establish a pattern.

IMO you should start by::

Checking the battery (voltage)
Checking the battery (CA/CCA)
Checking the alternator actual output in voltage and the diode function (at idle and load) (Midtronics system tester can check all these things)

After ruling out those items with proper test equipment, you can start looking for system shorts in high electrical drain components and looking for bad or disconnected grounds.

Just because the alternator seems to charge the battery at times without issue, does not mean it is good. It could be failing under load or temperature.

There are many variables in this issue, and double checking your work will not hurt you.
The next time you check it, it may be in failure and you might catch it.

Removing the fuses to certain sections completely eliminates the possibility that it could be the related component. Just leaving in the fuse in circuit because you don't see a drain leaves a path open.
 


ohsnapzitzmeng

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check the battery voltage, a good battery should be atleast 12.6v, and borderline is 11.6? weird things can happen but yea a diode in the alternator can go bad and drain your battery dead if all your fuses are good
 

civic939

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New alternator fixed the problem. $150 later. Bad diode in the alternator was my guess. Thanks
 


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