dead battery, but won't take a jump start???

O2GO4LO · 05-04-2009, 09:47 PM

Ok, first the background, Vehicle sat after a off roading trip without driving it for about 3 weeks. turns out that I left the FM transmitter (MP3 player) on. Stupid, I know. So I took the battery in, trickle charged it, load tested it, tested fine and all SEEMED to be ok.

Today, jumped in it, started fine, driving a minute or two after I left, " check guages" comes on.....the voltmeter was pegged out at over 19!!! I immediately turned off the road and shut it down..... turned the key back on and "bump started" it, as I was still rolling. Would not stay running.

Got under the hood, and from the black box (by the stock air box) was a rapid clicking sound (fuel pump relay I think) Called wife for a jump, after 30 minutes and multiple attempts vehicle would not do more than BARELY turn over, then nothing.

NOT ELECTRICALLY MINDED, but mechanically capable.....so, where do I start???

Side note: my neighbor (JEEPER) pulled me home!!! tow straps are not just for off-road!!

Rayvins · 05-04-2009, 10:41 PM

Just a guess, however sounds like a bad alternator. Not recharging the battery, so the jeep runs til the battery dies again.

Do your lights or anything else work?

dudeinatj · 05-04-2009, 10:43 PM

when my check gauges light came on and voltmeter pegged, it turned out to be a ground problem.

**compcrasher86** · 05-04-2009, 10:43 PM

check your connections to the battery. Make sure they are clean, free of corrosion, and tighten them down. weird things happen when your connectors are bad

dudeinatj · 05-04-2009, 10:48 PM

Quote:

Originally Posted by compcrasher86

check your connections to the battery. Make sure they are clean, free of corrosion, and tighten them down. weird things happen when your connectors are bad

that's what happened to me, left me stranded briefly until i figured it out.....a loose ground at the battery.

O2GO4LO · 05-04-2009, 11:17 PM

Bump....c'mon guys.....I need a place to start...

TMar · 05-04-2009, 11:22 PM

People have given you places to start.

Are the cables tight?
Check your grounds.
Have your alternator checked

In that order.

O2GO4LO · 05-04-2009, 11:38 PM

thanks all... I hadn't refreshed my page when I bumped.....I'll get back on it tomorrow. I'll start with cleaning and re-tightening the connections...

mikeb683 · 05-04-2009, 11:46 PM

to be honest sounds like the alternator to me i had the same thing happen to me recently was and xj. But it came out of no where not my rig.. but we drove it about 100 miles no problems. Let it sit for 20 30 minutes tried to start it and nothing.. jumped it ran fine, which is different from you, but i got it up the road about two miles and the gauges started shorting on me and she eventually died only to be jumped no problem again. Anyway we later discovered it was the alternator as she is and electronic ignition just like the tj.

O2GO4LO · 05-05-2009, 12:42 AM

OK....so I couldn't wait until morning, multimeter in hand, I just went to check into the problem. Battery = 12.4 volt (not running) Connections = 11.1 Cleaned connections, re-tightened, ta-da! starts right up. To be honest, I feel kind of stupid.

When it comes to electrical problems, I just seem to shut down. Thanks again to all that posted. I love this place!!!!

FYI: I did the alternator test after I got it started again(read elsewhere on this forum,) and that was good at about 14.1 volts!!

**4x4grey88** · 05-05-2009, 12:50 AM

Quote:

Originally Posted by O2GO4LO

OK....so I couldn't wait until morning, multimeter in hand, I just went to check into the problem. Battery = 12.4 volt (not running) Connections = 11.1 Cleaned connections, re-tightened, ta-da! starts right up. To be honest, I feel kind of stupid.

When it comes to electrical problems, I just seem to shut down. Thanks again to all that posted. I love this place!!!!

FYI: I did the alternator test after I got it started again(read elsewhere on this forum,) and that was good at about 14.1 volts!!

14.1 volts is okay/normal

Do you post in the San Diego section??? There are a bunch of us Jeepers in the San Diego section posters on Jeep forum.

mikeb683 · 05-05-2009, 12:56 AM

Great.. glad we could help and glad my diagnosis of the **** alternator was wrong

**compcrasher86** · 05-05-2009, 04:01 PM

Quote:

Originally Posted by O2GO4LO

OK....so I couldn't wait until morning, multimeter in hand, I just went to check into the problem. Battery = 12.4 volt (not running) Connections = 11.1 Cleaned connections, re-tightened, ta-da! starts right up. To be honest, I feel kind of stupid.

When it comes to electrical problems, I just seem to shut down. Thanks again to all that posted. I love this place!!!!

FYI: I did the alternator test after I got it started again(read elsewhere on this forum,) and that was good at about 14.1 volts!!

I knew this one from experience. My ZJ was stuck in a parking lot at school and had same exact symptoms as you. wiggled clamps to get it working and drove it home I literally had cracks through my connectors though (dont worry I replaced them)

**Jerry Bransford** · 05-05-2009, 05:14 PM

When the battery is completely dead, the engine won't run long after being jump started and it can't be push-started either. There MUST be a good solid 12 volts from the battery to provide the alternator its required "tickler voltage" which makes it work. When there's no 12 volts from the battery at the alternator, the alternator won't work and the engine won't run.

Yes, SOME other alteranators and all generators work fine when there's no battery or if the battery is dead but that isn't true for the type of alternator used in modern Jeeps.

Charge the battery fully and then everything should be fine if the battery is in otherwise good condition.

05-04-2009, 11:22 PM	#7
TMar Registered User Join Date: Aug 2008 Location: Ky Posts: 85 Profile Gallery Classifieds My Jeeps	People have given you places to start. Are the cables tight? Check your grounds. Have your alternator checked In that order.