Charging issue/Question -

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post #1 of 3 Old 10-17-2013, 01:42 AM Thread Starter
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Charging issue/Question

Hello all.

I have a 2002 Jeep Grand Cherokee Laredo. 6 Cyl/4.0. I am having a strange charging problem that I hope some one can help me with. It has a new alternator already, and the battery tested ok.

Here's what it's doing. Upon startup, the voltage gauge is fairly stable, it fluctuates slightly. As the vehicle warms up, it gets worse, and will vary between a little above 14 on the gauge, to almost down to 9 on the gauge, It does this continuoulsy back and forth, almost as if it's "Hunting". I'm questioning the PCM I guess, as well as the Battery Temp Sensor.

Also, sometimes at idle, the voltage will fall real quick, and the engine changes in sound, almost as if there was a sudden load put on the alternator. When this happens, I get a good amount of engine noise through a subwoofer I have in the vehicle.

Sorry for a long post, just trying to remember all the info I can for you. Thanks in advance.

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post #2 of 3 Old 10-17-2013, 09:47 AM
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1987 XJ Cherokee 
Join Date: Sep 2006
Location: 3rd rock from sun
Posts: 10,545
It sounds like you might have an intermittent systems ground.
I'd look around under the hood for grounding points to disassemble and clean.


"You can set my jeep on fire and roll it down a hill,
But I still wouldn't trade it for a Coupe DeVille."

COTY 2009

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post #3 of 3 Old 10-17-2013, 11:18 AM Thread Starter
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I cleaned up grounds from the battery and such. When it does fluctuate, it's steady. It's not like 3 seconds in between, then 10, then 5. It's slowly like back and forth. I almost question the regulator.
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