james750 Posted November 8, 2008 Share Posted November 8, 2008 Well this morning I went to start up the 97 and the battery was dead, So I pulled up the mj and used my brand new jumper cables to try and charge it up. About 5 seconds after plugging it in, the smoke started. i quickly unplugged it and checked, sure enough it had drained the whole battery. I went back and checked the jumper cables to find that it had a piece of insulation slit open allowing the + and - wires to cross. I was able to get the battery charged back up and everything was seemingly working. But would turn over but not fire up, I started feathering the throttle and it would start but it wouldn't idle, just shuts off when I let off the gas. The fact that it will stay on when the throttle is open makes me think either IAC or TPS, but what do I know. Any ideas??? Link to comment Share on other sites More sharing options...
HOrnbrod Posted November 8, 2008 Share Posted November 8, 2008 Good chance you fried the PCM. Link to comment Share on other sites More sharing options...
Sir Sam Posted November 8, 2008 Share Posted November 8, 2008 Well this morning I went to start up the 97 and the battery was dead, So I pulled up the mj and used my brand new jumper cables to try and charge it up. About 5 seconds after plugging it in, the smoke started. i quickly unplugged it and checked, sure enough it had drained the whole battery. I went back and checked the jumper cables to find that it had a piece of insulation slit open allowing the + and - wires to cross. I was able to get the battery charged back up and everything was seemingly working. But would turn over but not fire up, I started feathering the throttle and it would start but it wouldn't idle, just shuts off when I let off the gas. The fact that it will stay on when the throttle is open makes me think either IAC or TPS, but what do I know. Any ideas??? Same thing happens to me when the battery is low on charge, at high idle the Alt puts out enough current to keep the Jeep running despite a low battery. How do you know the battery was truely charged when you were able to start it? Usually for me this means running the engine at high RPM for a few minutes and allowing the battery recharge, then everything is right and good in the world again. Good chance you fried the PCM. This does not seem representative of a bad PCM. Link to comment Share on other sites More sharing options...
james750 Posted November 8, 2008 Author Share Posted November 8, 2008 Ill try leaving it at high RPM's for a few minutes tomorrow. I thought it was at full charge b/c with a multitester it read at about 12.5volts. Link to comment Share on other sites More sharing options...
Sir Sam Posted November 8, 2008 Share Posted November 8, 2008 Ill try leaving it at high RPM's for a few minutes tomorrow. I thought it was at full charge b/c with a multitester it read at about 12.5volts. Whats more important is how many amps the battery can put out, it can show full voltage, but not be able to output enough current to keep the jeep running. Link to comment Share on other sites More sharing options...
Eagle Posted November 8, 2008 Share Posted November 8, 2008 Ill try leaving it at high RPM's for a few minutes tomorrow. I thought it was at full charge b/c with a multitester it read at about 12.5volts. That could have been a surface charge. The only right way to test a battery is under load. For example, although it's not smart to make a practice of it, turning on the headlights and then hitting the starter gives you some idea of how much reserve capacity the battery has. If the lights dim out and the starter won't turn over the engine -- the battery isn't charged, regardless of what the voltmeter shows. The correct way to charge a battery is with a trickle or taper-charge battery charger ... and it takes several hours to fully recharge a dead battery. The industrial-strength fast chargers that shops use still require between 30 minutes and an hour to charge a battery -- and they are VERY hard on the battery in the process. It sounds like you just hooked the battery up to another vehicle for a few minutes and then started it. That's not enough to charge the battery. Link to comment Share on other sites More sharing options...
james750 Posted November 8, 2008 Author Share Posted November 8, 2008 No, I left in on my trickle for about 7 hours, I tried to use a vehicle to jump it but it obviously didn't turn out so well. But it could still be just a surface charge, as I don't have a Vat 40 to put it under load. Ill try it with the headlights on and see. One thing I noticed was that the charge guage was bouncing back and forth from pinned left (9>volts). The battery is still original so I'll probably replace it. Link to comment Share on other sites More sharing options...
Sir Sam Posted November 8, 2008 Share Posted November 8, 2008 No, I left in on my trickle for about 7 hours, I tried to use a vehicle to jump it but it obviously didn't turn out so well. But it could still be just a surface charge, as I don't have a Vat 40 to put it under load. Ill try it with the headlights on and see. One thing I noticed was that the charge guage was bouncing back and forth from pinned left (9>volts). The battery is still original so I'll probably replace it. Hmmm, well, how old is the battery? Any idea why it was dead in the first place? Link to comment Share on other sites More sharing options...
james750 Posted November 8, 2008 Author Share Posted November 8, 2008 yeah, its a 2000 factory battery. :eek: Today was actually only the second time its given me a problem since I got the vehicle 5 years ago. :D Guess its about time to get a new battery. Link to comment Share on other sites More sharing options...
Sir Sam Posted November 8, 2008 Share Posted November 8, 2008 yeah, its a 2000 factory battery. :eek: Today was actually only the second time its given me a problem since I got the vehicle 5 years ago. :D Guess its about time to get a new battery. Uh ya, I'd say thats yer problem right there. Link to comment Share on other sites More sharing options...
BLHTAZ Posted November 8, 2008 Share Posted November 8, 2008 Yeah...I'd say it's battery time. I have never had a regular battery last more than 3 years. My Yellow Top made it almost 7 years before needing to be replaced. What baffles me is that once it's started, it should run off of the alternator with no problem... :hmm: . Why is it not doing that? Could there be an alternator & battery issue? I have run vehicles many times on a dead battery, and even a couple times with no battery in them at all without a problem as long as it was kept running...RPM did not matter. Link to comment Share on other sites More sharing options...
aemsee Posted November 8, 2008 Share Posted November 8, 2008 Could be that the battery has an internal issue that is taking everything the alt can put out at idle. How are the terminals? You could have high resistance in the connection btwn the terminal and the cable. Do a voltage drop test. But, as others and yourself have said. Probably time for a battery, especially if it says MOPAR on it :). Link to comment Share on other sites More sharing options...
maddzz1 Posted November 8, 2008 Share Posted November 8, 2008 Have you checked the battery cables. If they are the original (or just old) cables they could be in bad shape. If the insulation is torn and it is touching on something that could be your problem. Link to comment Share on other sites More sharing options...
james750 Posted November 8, 2008 Author Share Posted November 8, 2008 I'm pretty sure its battery, Ill change it out today, probably not cables as it didn't have the problem b4 the jumper cables fried it. Link to comment Share on other sites More sharing options...
james750 Posted November 8, 2008 Author Share Posted November 8, 2008 new battery and terminals fixed the problem! :D :thumbsup: Link to comment Share on other sites More sharing options...
BLHTAZ Posted November 8, 2008 Share Posted November 8, 2008 new battery and terminals fixed the problem! :D :thumbsup:Glad to hear it. Did you check the cables over very thoroughly as well. Link to comment Share on other sites More sharing options...
james750 Posted November 8, 2008 Author Share Posted November 8, 2008 yeah, the positive terminal was fried as was the first part of the wire going into it but farther back it was all ok. :cheers: Link to comment Share on other sites More sharing options...
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