my car always starts like a charm if i start it every day and let it sit for 5 or so minutes, long enough to get a smooth idle. well whenever i leave it sitting for 2 weeks its always dead. the battery is brand spankin new it hasnt even been on the road yet. when i tur the car off EVERYTHING is off no lites no stereo and so on. what could be drawing the power from the battery? why does it keep going dead? is this normal? no other car has done this to me. lik i said its always reliable if i let it sit running once a day but when i dont it is totally dead, theres nothing no sound when i try to start it its totally dead. please help me solve this so i dont have to worry about it when i get my license back in a month. thanks

 

Wild guess, alternator has shorted diode. This is common.

If you want to search problem, you must remove battery negative connector, and put a ampmeter between. Check how much car takes current when everything is off. Then start disconnecting fuses, one by one. When current goes near 0, you have found faulty circuit.

 

ok so lates say i wonder along a ampmeter and i do this.. do i just replace fuse? o and does the battery need to be rejumped and charged again? or do i do this ampmeter as is?

 

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yah i have to have my step dad jump start it everytime. im guessing that he is right when he says the diode. when i use a charger on the battery while it is still hooked up. it doesnt really do much so im guessing the alternator is drawing what i charge right back out and i did a search of this. but no one says how to truly fx this as in how to get to it and replace it, only how to figure out the problem wich is now i think obvious but now i need to kno how to fix it. if i have to ill wait till i get my license back and take it to a auto zone but really want to have a smooth running car for when i get it back and i cant take it anywhere to be fixed until i have my license.

 

Ever think of looking for a vanity or glove box light left on?

Running the engine for a few minutes will not give the battery a decent charge. Try using a battery tender when the car is not in use.

Do a search for "battery tender". Lots of good info out there.

 

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OK, I have this problem alot. It is a pretty simple fix. Start it every day. Just because everything appears to be off, it really isn't. The computer is still up and running and draining that brand new battery. When I am going to leave the car sit for long periods of time I put a battery tender on it.

 

You could take the alternator to a place that rebuilds starters and alternators. They could verify that this is the problem, and then fix it. The diodes are built into the alternator.

Or next time you let it sit for a week. Keep the battery cable disconnected for the week. If it starts right up, it is not the battery, something in the car is slowly draining the battery. Diodes??

 

If the battery goes dead after the car sits for a couple of weeks, that tells me that you have a slow drain and/or a battery without much life left.

First things first, always charge a dead battery, never let the alternator do it. That's a sure fire way to kill an alternator, and a battery, for that matter.

 

yah im thinkin when i get my license back i will have it jump started. run it around town for the day to get some life in the battery and use the disconnect method. it seems simplest. every other time it has been jumped it has ran the next day when i went to start it so that should be cool. i had no idea the car still drew power while totally off and no lights on.

 

well nevermind that idea...

 

If you want to find the cause, you must find out, what is sucking current from your system.

Easy way:

- Disconnect battery negative terminal
- Charge it full with battery charger
- Connect ampmeter (included in any cheap voltmeter you can find in the shop) between battery negative terminal and ground lead you removed. Put voltmeter to scale "10A"
- Don't try to start car or put ignition to "on". Just let it sit, and make sure that there is no lights on inside or hood. If so, you can take off courtesy-fuse to get rid of those lights at this point.
- Check reading, it should be very near zero. If it is bigger than 0.5A, you battery will go dead after some time. For example, if car takes 1A current when everything is off, your battery will be dead after 50 hours, if you have 50AH battery. Of course, in real, it will be unstartable after about 30 hours in that case.
- If reading is bigger than zero, unplug alternator. If reading is now zero, then alt is gone.
- If you still got current, start to remove fuses, one by one. Check reading after any fuse. (You can put fuses back just after checking). This is the way to find out, what circuit is the bloodsucker.
- When you find, what fuse causes current flow, then we can check out more specifically, what can be the real cause.

It is easy to do, and saves your battery and alt in the future. Your alt has to charge battery every time after car sits a while. It does not good to it. Alt is already weak part of this car. Don't make it worse

 

MORGAN - has the correct approach to resolve the problem methodicaly. You should have under 30 ma (thats .030 amps) when nothing is on and it is just sitting there. My 94 measures 25 ma and if something should change I know what my normal current is.

TORCH - has a good idea also if you have the time to leave the car to sit for a while. Just in case you had a bad battey and you would not go off working on the car unnecessary.

Years ago clocks use to be the bad guy with these problems.

 

Clocks and Alarm systems are still pulling on the battery. We all had the discussion about disconnecting the battery and the ECM losing info etc. I don't think you battery is bad.

There are quite a few things that are "trickle" draining your battery. A trickle is the absolute best way to charge a battery and the absolute best way to completly drain one.

You may want to buy one of those little Solar chargers that plug into the Cig Lighter and lay on the dash.

 

check the light on your rearview, it's easy to accidently switch on when you are adjusting the mirror and can not tell it's on until dark outside. just a thought, this happened to me once..