I have a 2003 kj limited 3.7, with a weird random charging issue. Long story short, I found a ghetto wiring job from being towed behind an rv.

Here is all of the related wiring, which consisted of burnt converters, chafed and bare spots, and resistors for who knows what.


The problem I'm having is completely random, and I cant seem to make it happen. It starts with the front speakers crackling and alternating sides, then progresses to hearing engine noise through them. Adjusting the volume on the radio does nothing, and it happens on fm/am/cd/aux. The noise stops if I turn the radio off. The speaker noise gets louder with acceleration, and quiets when I let off the throttle. It stops when I turn off the radio, or shut the rig off. Shortly after the noise the battery light comes on, and voltage drops anywhere between 5v-12v. Eventually the lights start to dim and it will shut down. This is the only time that voltage drops below 12.5v with the engine running. It will eventually work itself out and voltage will jump to 13.5-14.5v. Im getting a p1682 low voltage code after it happens. Also, if I pull over and unplug the radio during the episode, it still has low voltage. It doesn't do it all of the time, and will go a day or 2 without a problem. I noticed this before and after I removed the rv wiring. Battery voltage is always 12.79 with engine off, and never drains, and never turns "slow"

Here's what I've done or tested:
1)Alternator bench tested good at 2 different places.
2)Battery tested good at 2 stores, bad at one.
3) Replaced the radio with an aftermarket HU, then later added a ground straight to the battery, and also grounded the hu case like in my tj.
4) Cleaned all power/ground connections, and checked for resistance and continuity.

This one has me stumped. I've gone through and checked the field wires for the alt, and all power and ground words. I've even added 10ga wiring like the "big 3" upgrade. Nothing I've done changes anything. Could the alternator be on its way out, but still test good? I've even moved my amps ground, power, and rca's around with no change. Also completely disconnectingy sub and amp doesn't help. It seems to do it more after the rig has been driven for a minute, and rarely when cold. I even replaced the battery with no change. Anyone have ideas on what to do next?

Sounds I THINK like an alternator diode may be failing with heat or load. When it happens again check for AC voltage at the battery with the engine running. I do not remember the spec. but seems like anything above .6V AC is to much, someone please help with a spec, and indicates a bad diode. I don't envy you that chase, the field control(voltage regulator)is part of the PCM so be sure to ck it,s pwr. and grounds. Good luck with it ...Pete

The_dealer has basically fixed his problem.....from lots of advice on jeepforums.com where he first posted his problems.

Several problems fixed but mainly the Alternator was arcing inside....replacement of Alternator seems to have fixed his problem.

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2002 Export CRD 2.5 Sport