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Old 06-30-2010, 11:50 PM   #1
Join Date: Mar 2006
Posts: 5
Help Won't Run

My TJ won't run unless it's jumped and dies as soon as you take off the jumper cables. I was told the voltage regulator is in the computer. So do I need to get a new computer???? Or is there another fix????

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Old 06-30-2010, 11:55 PM   #2
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I think the regulator is in the alternator, you should get your alternator tested.

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Old 07-01-2010, 12:32 AM   #3
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X2 on the alternator. Any parts store will be able to check it for free. Check all your cables to make sure they are not corroded.
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Old 07-01-2010, 07:23 AM   #4
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Also, if the battery is weak, bad or the voltage is off, the computer will shut the vehicle right off. It is common in Chrysler products. I had this with my Jeep, my Durango as well as other on forums. Have the battery tested.
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Old 07-01-2010, 09:07 AM   #5
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Will it crank, but not turn over or is there nothing but a click (and possibly what appears to be possessed guages, tach and speedo jumping around). If so then it is probably your battery. Have your battery tested or borrow one from another vehicle to test if that is your problem. Check your cables and connections. Clean them with a wire brush to remove any and all corrosion. Make sure that the connections are tight as in once they are connected they cannot be moved at all. Before you start replacing parts, check the easiest and cheapest first.
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Old 07-01-2010, 11:03 AM   #6
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Thanks, I did have the alt tested and it is fine. the parts store told me the voltage is regulated through the comp.
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Old 07-01-2010, 11:12 AM   #7
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If the gauges are going wild - jumping up and down, it means you have low voltage to the system.
- try jumpering it from another GOOD battery with GOOD jumper cables.

If still no go - your battery may be dragging it down if it's internally shorted.
Disconnect your battery - clip the jumper cables from the other battery to the cables. If it still makes no difference it's not the battery.
Reconnect it.

Next check the connections on BOTH cables at BOTH ends. Feel along the cables for any signs of swelling - sometimes a cable will corrode under the insulation - it usually swells a little there.

Try using the jumper cable to run from the (-) post of your battery to engine ground - that checks the (-) cable.

Try jumpering between your (+) post to the starter with the jumper cable. That checks the + cable.

Look at the connections in the relay box at the firewall end where the battery cable brings power into the box.

Your battery simply isn't able to supply enough current to the system - bad battery or resistance somewhere. It's not your alternator - alternator is not used for starting.
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Old 07-01-2010, 04:46 PM   #8
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Thanks rrich. I will check it out!!!!

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