Battery Drains After 1 day - no electrical knowledge, need help

[kenny 84 CJ7]

Hello all,

I have an 84 CJ7 with the AMC 258 i6 / 4.2l . Its starting to get cold and I know that can affect the battery, but recently it has been draining down to supper low. Once I jump it the battery reads 14.6v on the volt meter. I normally drive it around for a while to give it a good charge. Like and hour or so. It will then read about 12.4v but starts to drop imediatly. 12 hours later maybe have 6v.

Not sure what it might be. I have read that grounds were always bad on the old jeeps. Could this be slowly shorting out the battery?

Any help would be great. No real electrical experience.

Thanks

Eoin

 

[ridegnu]

Start with the battery. How old is it? Has it ever had new acid?

You may have a short to ground or a bad relay. If you can get an ammeter hok it up on the positive battery cable and see if you have a draw. When I had a problem like this on my truck by battery was having a constant .3amp draw on it when the engine was off. Then pull your fuses one at a time, check the meter for change, replace fuse. I did this till I got to my blinker relay and when I pulled that out the draw on the battery went to 0amp. Went and bought a new one, problem solved.

 

[Kilo19]

Jus an FYI when a battery drains to zero, esp in the cold. There petty much useless. Happened on my truck. Left the inside light on over night dead in the morning charged it ran it for an hour driving to work. 8 hrs later batt dead and it was less then 3 yr old. Got a new one and good as new. Except for my wallet is lighter.

 

[ThisGuyUKnow]

Hello all,

I have an 84 CJ7 with the AMC 258 i6 / 4.2l . Its starting to get cold and I know that can affect the battery, but recently it has been draining down to supper low. Once I jump it the battery reads 14.6v on the volt meter. I normally drive it around for a while to give it a good charge. Like and hour or so. It will then read about 12.4v but starts to drop imediatly. 12 hours later maybe have 6v.

Not sure what it might be. I have read that grounds were always bad on the old jeeps. Could this be slowly shorting out the battery?

Any help would be great. No real electrical experience.

Thanks

Eoin

Just a little info. When you say you jump it the meter reads 14.6 that is not the actual charge of the battery that is how many volts your alt is cranking out. When running the alt puts out more than 12 volts to charge the battery as well as run your peripherals. I would have your battery tested at the autoparts store. My thoughts are that its a bad battery and just isnt holding a charge.

 

[ksouthw80]

Try this. With the battery charged, disconnect the positive bat terminal, then make contact with the terminal end and pos of the bat and see if you see any sparking, this means something is drawing on the bat constantly. least you'll know

 

[ThisGuyUKnow]

Try this. With the battery charged, disconnect the positive bat terminal, then make contact with the terminal end and pos of the bat and see if you see any sparking, this means something is drawing on the bat constantly. least you'll know

If the radio has a memory or there is a clock this will cause a spark

 

[ksouthw80]

Good call!

 

[kenny 84 CJ7]

Start with the battery. How old is it? Has it ever had new acid?

You may have a short to ground or a bad relay. If you can get an ammeter hok it up on the positive battery cable and see if you have a draw. When I had a problem like this on my truck by battery was having a constant .3amp draw on it when the engine was off. Then pull your fuses one at a time, check the meter for change, replace fuse. I did this till I got to my blinker relay and when I pulled that out the draw on the battery went to 0amp. Went and bought a new one, problem solved.

Sorry guys, I meant to post that the battery is less than 10 months old. I replaced it when i bought the jeep back in march of this year. This is a good idea though, I will test for a draw on the battery tomorrow after work.

Also want to apologize for the slow response. I don't seem to be getting emails when I get replies to my posts anymore. Not sure why.

 

[kenny 84 CJ7]

If the radio has a memory or there is a clock this will cause a spark

No radio, but i do have a clock (stock). It only works half the time and does not keep accurate time. Would this cause a draw on the battery when i test it? If so, i could disconnect it and look for a draw then.

 

[Hedgehog]

First, clean your battery terminals, both the posts and the clamp. Charge your battery with a battery charger, believe it or not an alternator will not charge a dead battery. Why, I really don't know but that is what is fairly common knowledge. Disconnect a terminal and let it sit over night and see if it will start in the morning. If it will you have a drain on your battery. Or you can go to a parts store and they will diagnose your charging system.

Even if everything checks out, your battery is likely done. Lead acid batteries don't like being discharged. Every time it happens the life of your battery is seriously reduced.

 

[ThisGuyUKnow]

Sorry guys, I meant to post that the battery is less than 10 months old. I replaced it when i bought the jeep back in march of this year. This is a good idea though, I will test for a draw on the battery tomorrow after work.

Also want to apologize for the slow response. I don't seem to be getting emails when I get replies to my posts anymore. Not sure why.

10 months old does not mean the battery is good. Especially if it got discharged multiple times. the clock draw should not be enough to kill your engine over night. If it was it wouldnt make any sense to have one. an autoparts store can tell you real quick if the cell is bad or not even if you bring it in dead. Either way Id take it in and exchange the battery. I have yet to see a battery manufacturer that doesnt have a free replacement policy for batteries under a year old that go bad.

EDIT: If you can Jump the jeep and drive it to the autostore. Park it an leave it running and have them test your alternator as well. Just because your gauge is reading 12v+ doesnt mean your alternator is good. It may not be putting out any amps. Without amperage your battery would not be charging after you jump the car and cause this issue.

A bad battery that wont hold a charge can cause the alternator to prematurely go bad because the alternator is working a lot harder and cranking out alot more volts and amps trying to charge the battery. Conversely a bad alternator can cause the battery cell to go bad prematurely because it isn't charging the battery after starts causing the battery to drain till its dead over and over.

 

[kenny 84 CJ7]

Update:

Thanks for all your help so far. I went through everything today and found that the problem was in the ignition. The key was staying engaged even after the jeep had been turned off and and was sitting. This was keeping a constant draw on the battery. I took out the ignition lock cylinder and replaced it. Seems to have solved the problem.

I am going to keep an eye on it for now. The battery seems to be ok. I plan on getting it tested at the auto parts shop. If its bad i might be able to get another on warranty.

Thanks

 

[Hedgehog]

Wow, that was easier than the usual "Battery goes dead" scenario. Great recovery. Did the key/lock act or feel odd?

 

[Torxhead]

You now have "Electrical Knowledge".

 

[kenny 84 CJ7]

Wow, that was easier than the usual "Battery goes dead" scenario. Great recovery. Did the key/lock act or feel odd?

I don't know if I would say it felt odd being that it is the original key cylinder. I had noticed the key not releasing a few times over the summer. I would have to turn the key back and forth before it would release. Sometimes it would it felt like the key turned past the off positions and would not release from the cylinder. After I took it apart it looked worn out inside. May have been tampered with some time in the past (#POproblems).

 

[Hedgehog]

The death of car key cylinders ..... all the other junk hanging on the key ring. It isn't unusual for this to happen. My '80 Jeep didn't need a key once it was in the run position. you could pull it right out. It was handi, but one day I shut it off without the key and had to walk a ways to get it.