battery keeps dieing Dont know why.

65stang289 · Sep 24, 2006

I turn off all my switches fan,lights,fuel pump, radio, nothing else is on. I left to go out of town for a week and came back and it was dead. I killed my red top I charged it and put it back in there. I can drive the car around for 15-20mins shut it off and try to start it and it acts like it has no juice. I had the alt. checked out it was good I put this battery in my mud truck and its fine. Oh yeah the battery is in the trunk if that matters any I dont think so.

Pakrat · Sep 24, 2006

Well normally I would say it has a dead cell which can happen even on a brand new battery but if you say there are no issues with the battery in your truck then you have a power draw somewhere there shouldn't be. You should get a voltage tester and check each connection from one lead to the next. I have an old Dixco multi tester which they don't make anymore but you can pick up a simillar one at any parts store. They come in handy for a variety of things and no hobbiest should be without one as these cars have constant gremlins. First check your ground from the battery to the engine block (always a likely candidate at the block) then onto the solenoid etc and so on, you'll find it.

fvike · Sep 24, 2006

I had a similar problem last year. Turned out to be the electric fan relay that was wired up wrong.
It didn't drain the battery as fast as yours dough.

Fastback_1 · Sep 24, 2006

Very good chance your voltage regulator is bad.

justford · Sep 25, 2006

Did you try the old letting the car run and disconnect the battery cable to see if the engine dies test?

67Dylan · Sep 25, 2006

justford said:
Did you try the old letting the car run and disconnect the battery cable to see if the engine dies test?

Did you know that is a terrible idea? If you want to check the battery/alt go to a auto parts store (checker, auto zone or whatever you have w/in your region) and let them check it for FREE.

What is your voltage while the car is running? How about when it's not running? Do you know how to check for draws (current draw)?

SoCalCruising · Sep 25, 2006

Yeah, sounds like a power draw somewhere. Mine was in the alternator wiring harness that the PO hacked when installing a 1-wire alternator. I put in a new alt harness and switched to a 3G alternator. Goodby dead batteries.

krash kendall · Sep 25, 2006

The ligh tin the glove box wasn't turning off when I closed it. It took me forever to figure that one out. Park the car for a week and that little bulb would slowly kill the battery.

You can put a meter inline with one of the battery terminals to see if any current is running with the car off. If so, then start popping fuses out untill the currrent stops and you will have found the curcuit that has the drain.

TheMetriX · Sep 25, 2006

I've had problems with my horn draining my battery. The horn button assembly is crap, so when I close my door, it tends to make the button fall off from time to time. If I don't fix it right away, it drains the battery.

1966conv · Sep 25, 2006

I've had an optima fail in 6 months, bad cell. Charge it real good and take it for a load test.

1320stang · Sep 25, 2006

67Dylan said:
Did you know that is a terrible idea?

Explain?

NasaGT · Sep 26, 2006

Sounds like multiple problems here.

1) "Drive car for 15-20 minutes and battery has no juice." If the alt tested good, then either the voltage regulator is bad, or you have a problem with your wiring for the battery. What guage wire did you use to move the battery to the trunk? Check the voltage at the battery with the car running. Should be at least 14 volts.

2) "Park car for a week and battery dead." As described by others probably a slow drain. These are hard to find. I like to start with a charged battery, measure the voltage of the battery disconnected form the car. Connect to car and measure again. If lower, then start pulling fuses until it returns close to its original voltage. This will help you find the circuit the drain is in.

jasonn · Sep 26, 2006

NasaGT said:
Sounds like multiple problems here.

2) "Park car for a week and battery dead." As described by others probably a slow drain. These are hard to find. I like to start with a charged battery, measure the voltage of the battery disconnected form the car. Connect to car and measure again. If lower, then start pulling fuses until it returns close to its original voltage. This will help you find the circuit the drain is in.

Yep, I check kind of the same way. But I take the negative cable off of the battery. Then hook one end of a test light to the the battery cable and the other end of the text light to the - bat terminal. If it has a draw capable enough drain the battery, it will light your test light. Then start pulling one fuse at a time until your light goes out. That'l give you an idea where to start looking. Seen ALOT of cigarette lighters short out.

67Dylan · Sep 27, 2006

1320stang said:
Explain?

The battery helps stabilize the pulsating DC current from the alternator. W/that said a couple of things can happen: First, pulling a battery cable causes an arc and we know arcs aren't good. Second, the alternator starts to overcharge; it has current, but where does it have to go? The alternator/charging system can go bye-bye, plus other components can go south as well. Spending money needlessly isn't what most of us want to do.

1320stang · Sep 27, 2006

Okay, arc I understand, but all he's talking about doing is to pull the cable to see if the car dies or not. It's a simple method to confirm if the alternator is working or not. It's not like he's driving the car 20 miles. I've had a car at my place that didn't have a battery and I jumped it with cables to move it somewhere else, ran maybe 2-3 minutes. I drove the car to work today (with a battery) with no problems. Also, we're not talking a computer controlled vehicle, other than maybe an aftermarket radio, I can't think of a whole lot to go wrong other than the age of the system. I live 10 miles from the nearest Auto Zone, 20 miles and a hour+ to remove, drive, test, find out it's okay, drive, reinstall = pain in the arse.

1320stang · Sep 27, 2006

I asked an electrical engineer about this and this is his response:

He's right, sorta.

The "charging system" contains a great big capacitor to work with the rectifiers to turn AC output from the alternator coils into a clean DC source. That capacitor also happens to be used as the starting battery. The combination of rectifiers, voltage regulator, and capacitor combine to create 13.8VDC.

Without the battery, the voltage will not be adequately filtered and the DC output from the alternator/regulator will be messy. On an older car it's probably not a big deal. As the amount of electronics in the car increases, the chance that there will be a problem also increases. Sometimes a cheap radio will have a distinct hum or whistle if the battery isn't in place.

Pulling the battery for a few seconds to see if the engine dies probably won't hurt anything. If it does make something fail, that something was probably already getting weak.

I drove a car from Emporia to OKC without the battery once. The battery terminal had broken right off. A Kansas Highway Patrol guy gave me a jump at a gas station, and I drove on home. Never had a problem (that I know of) related to the battery thing.

battery keeps dieing Dont know why.

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