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Old 01-24-2010, 10:14 PM
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as usual from me, an elementary question from an eager, but green, jeep owner:

my 02 X wouldnt turn over, but did start with a boost. Driving around, the "Check Gauges" light came on; I turned off the ignition AND my gauges started jerking erratically (with key out) and then jeep wouldnt turn over at all.

Q1: sound like the alternator?
Q2: is the alternator pretty easy to replace? i imagine correct belt-tightening is the biggest hurdle?

any help, advice would be great. thanks
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Old 01-24-2010, 10:27 PM   #2
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No, that sounds exactly like a battery that is too dead for the alternator to work. The type of alternator used in our Wranglers requires a good solid 12 volts from the battery, which is called a "tickler voltage", before it can put out any power. Our engines will not run for long if the battery is removed or completely dead, unlike some other vehicles with different types of alternators that don't require battery voltage or older generator-equipped vehicles.

If the battery is too dead, you might get the engine started with a jump start but the engine will run like crap because neither the alternator nor the battery is putting out enough power to power the ignition system.

Give the battery a good overnight (!) charge and try it again. If that doesn't do it, odds are the battery is toast. An auto parts store can verify that with a load test. Do give it a good overnight charge first though.

Edit: I STRONGLY doubt it is a bad alternator. I would bet $$$ it's the battery.

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Old 01-24-2010, 10:30 PM   #3
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What were your gauges reading when the "check gauges" light came on? What did the "battery gauge" read?

Q1: Yes, after removal, before purchase, have it checked. The parts store will do that for you (NAPA, O'Reilly's, Auto Zone, etc)

Q2: Very easy
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Old 01-24-2010, 10:47 PM
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JerryB: thanks for the advice. i don't have any way to give it an overnight charge, but could pull it for a load test tomorrow. when i did get it jumped off it didn't seem to run poorly, though. (and ive said it before: the apostrophe quote is great!)

wyo: thanks. the gauges were all reading normal (that is to say, in midrage. When it came on, i did exactly what it said: i checked them! ha. though i refer to my "green" comment. I might not have noticed small anomolies.)
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Old 01-24-2010, 11:36 PM   #5
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Im having the same issue. I took my battery in and got it check, (fine) and got a load test done (also fine). But still, I was either dying or hard to start. I started doing a ground search and found numerous open ended wires under my dash (from the old stereo system from the last owner). That would drain a battery as well and prevent it from charging fully. I still would like to upgrade my alternator to a high performance "anti tickler voltage" one. Anybody know of a good one?
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Old 01-25-2010, 08:14 AM   #6
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jconway, my Jeep did the same thing in the parking lot at Walmart but started and ran fine with a boost. I took it to the back of the store to the tire shop and had it checked.....dead cell. New battery and it has been running fine for the last 3 months.
I guess 7 years on the original battery was pretty good!

Have the battery checked but if it's got some age on it (like mine) have it replaced.
Good Luck!
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Old 01-25-2010, 08:28 AM   #7
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One other small point here. When you pull your battery, check your wires and connectors. Any amount of corrosion, no matter how insignificant it may seem can cause your battery to drain. Clean everything (I suggest using a wire brush on terminals and connectors) and make sure that the connection is tight. I went through the same thing and I agree with Jerry (he knows more about these things than anyone) It is your battery.

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