Why wont my jeep start????

[offroad30]

I recently just added two sets of PIAA lights and a 9.5ti Warn Winch the battery has been disconnected for about two weeks, because i added a few other things as well. But today i started it and drove to work, everything was fine, but at the end of the day when i was getting ready to come home it wouldn't start...!! i got some jumper cables and got it started, so i figured that the battery just drained for some reason, but when i got home, i shut off the engine and tried to start it again but it wouldn't. I thought it would start because the battery had been charging for about an hour while the jeeps engine was running. Does anyone have any ideas why this would happen, im not really sure but could a new battery help. It cant be the starter or alternator because i got the engine to turn over right????

[old school]

might be a draw depending on how you wired the lights up disconnect positive battery cable hook a meter to the post the other side to the battery cable genral rule of thumb souldnt be more then .75 amp draw and load test battery.

[cptmax]

Get your battery checked; it sounds to me like it's bad. Of course, maybe there's a short after the electrical work.

[mtg1993]

Get your battery checked; it sounds to me like it's bad. Of course, maybe there's a short after the electrical work.
Get it started and take it to Autozone they can tell you if your battery or alternator is bad in like 5 minutes!:D

[RokNRich]

X2 on taking it to one of the discount part places. Could be a bad battery, but you could also have a short pulling current which killed the battery. You'll need to fix the short or you'll just kill the new battery as well. I'd get an optima or something cool if you need a battery :)

[mtg1993]

You can also test it yourself with a multimeter at home....a battery must stay at 12.50v for it be a good battery and if you get it started check the battery again and you can tell if the alternater is working by it charging 13.50 to 14.00v!!

[RokNRich]

You can also test it yourself with a multimeter at home....a battery must stay at 12.50v for it be a good battery and if you get it started check the battery again and you can tell if the alternater is working by it charging 13.50 to 14.00v!!

That works really good to see if your alternator is charging or not, but sometimes shorts are hard to find. I think the rigs at auto zone can actually check current drain, most meters won't pick up a small drain.

Also, if you have LED's and jusy rigged your relay so that it won't flash fast, there is a drain on the battery which only presents as dead after a few days.

Good luck, electrical problems can be a pain for many.

[LOWTECH]

Lowtech check for shorts:

Disconnect the battery positive cable with the engine off and put a 12 volt light between the positive terminal on the battery and the disconnected positive battery cable, if the light comes on you have a short.

Oh yea make sure your doors are closed, the light under the hood is off and the interor lights are off.

[RokNRich]

Lowtech check for shorts:

Disconnect the battery positive cable with the engine off and put a 12 volt light between the positive terminal on the battery and the disconnected positive battery cable, if the light comes on you have a short.

Oh yea make sure you doors are closed and the interor lights are off.


Yeah, that will work.

:)

[Stu Olson]

might be a draw depending on how you wired the lights up disconnect positive battery cable hook a meter to the post the other side to the battery cable genral rule of thumb souldnt be more then .75 amp draw and load test battery.
I did that just the other day on my TJ.....I had a faulty radio that was pulling current even though the ignition switch was off (as was the radio).

The IOD (ignition off draw) for a TJ is 5 to 25 milliamps, per the FSM. Once I got things fixed on mine, I checked it again....it was just a bit over 20 mA. For the math challenged, that is .020 amps. (not very much)