Dead Jeep

It's a '98 XJ 4.0 w/100,000 miles. It just died on me no power what so ever. I think it's the battery or the alt. . I will not turn over, but when jumped it will start if you stay on the gas. Soon as you let it try to idle it shuts off and goes back to black. I beleive it's the orignal alt. and do not know how old the battery is. Any one ever had this problem? If so please help out. Thanks

skylo said:

It's a '98 XJ 4.0 w/100,000 miles. It just died on me no power what so ever. I think it's the battery or the alt. . I will not turn over, but when jumped it will start if you stay on the gas. Soon as you let it try to idle it shuts off and goes back to black. I beleive it's the orignal alt. and do not know how old the battery is. Any one ever had this problem? If so please help out. Thanks

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Have your alternator tested. It sounds like that might be your problem.

Kevin

Its not your alternator. its your battery. I have seen this many times and everytime it turns out to be the battery. we are talking 100% dead, quite possibly an open circuit internal to the battery. an alternator needs to see a load in order to work. maybe there is an electrical guru that can explain in more detail. try a new battery before you go tearing out your alternator. battery is much easier to R&R...

skylo said:

It's a '98 XJ 4.0 w/100,000 miles. It just died on me no power what so ever. I think it's the battery or the alt. . I will not turn over, but when jumped it will start if you stay on the gas. Soon as you let it try to idle it shuts off and goes back to black. I beleive it's the orignal alt. and do not know how old the battery is. Any one ever had this problem? If so please help out. Thanks

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I second Rawbrown, check the battery and its connections first. The failure to run properly is common when a battery is so dead that it doesn't pull current from the alternator. The engine electronics don't like raw alternator output.

I have had similar problems in the past, by the way. It's not the most common failure mode for a battery but it happens.

Thanks alot guys. It was the battery. I put a new one in and it fired right like a Jeep should.