Battery, Alternator, or what? -
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post #1 of 3 Old 01-10-2011, 04:05 PM Thread Starter
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1997 TJ Wrangler 
Join Date: May 2010
Location: Meriden, CT
Posts: 29
Battery, Alternator, or what?

A few months back (Oct'10), our alternator finally died. This, after, we got a new battery and everything! So our Halloween gift to ourselves was installing a new alternator to go with our new battery.

A couple of weeks ago, I noticed that on certain occasions (when the weather got very cold, in the negatives and single digits overnight), the jeep would get the "check guages" light and the battery guage went to "red" (I don't know if that's 0, or negative). The Jeep error code read 12, 47, 55. I know 12 & 55 already, but 47 was a new one for me. Anyway, after turning the Jeep off and then back on, it ran just fine.

Then that problem seemed to stop, but occasionally I'd get a random energy surge when driving 40-45 on a very hilly road.

Today I ran into some major problems getting home from work. Once the jeep got to about 40-45mph, it would backfire, and the battery, fuel, tachometer, and spedometer all fell and then quickly went back to normal. The "battery light" also flashed. The fuel guage also seemed to move between 1/2 tank and 1/4 tank the entire trip between backfires.

I got onto the highway and it ran fine for 90% of the trip, until I got to a hill (it seemed to do most of its backfiring on little hills, but that could be coincidence).

**I forgot to originally add that upon arriving at home I checked for error codes once again. This time I only got 12 & 55, no more 47. Weird, huh?**

The last thing I need before a major snowstorm is more jeep problems. It seems to be an every 3-mo occurance nowadays and I'm just tired of it.

Does anyone have any ideas of what this may be? I'm guessing it's electrical, and probably not a spark plug issue, but again, that's just a guess.

Thanks, folks!

Last edited by rockinkiwi; 01-10-2011 at 04:14 PM. Reason: Left out a bit of information.
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post #2 of 3 Old 01-10-2011, 04:59 PM Thread Starter
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1997 TJ Wrangler 
Join Date: May 2010
Location: Meriden, CT
Posts: 29
BTW, this is also my daily driving vehicle. I live about 30 minutes from my work, a lot of it very hilly. I'm very concerned about making the trek to work in the AM.
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post #3 of 3 Old 01-10-2011, 09:26 PM Thread Starter
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1997 TJ Wrangler 
Join Date: May 2010
Location: Meriden, CT
Posts: 29
**bump** (I normally never do this, but I haven't received any views, much less responses). If anyone could please help or offer some ideas on how to repair this, I'd appreciate it. Thanks!
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