skyd

My Questions: Could a bad PCM fry an Alternator? and How can you tell?

During the last week or so, I have replaced 3 alternators(on number4) and purchased a new battery.

I picked up the Jeep about 5 months and needed a new engine, so I am not aware and have no knowledge of any issues prior to this.
after I got the engine running, I noticed the battery wasn't charging. tested the system and signs pointed to the Alternator.

1. Alternator 1 producer code P0622(Field something or other) took it back.
2. Alternator 2 had it in and ran errands to multiple places over a few hours. while on the backroads, we swapped drivers and stalled it(manual trans). wouldn't start up. Waited for AAA, got it jumped battery registered around 11.9v Got new battery next day. new battery died, system wouldn't charge. Took the running jeep to Advance(never again) they tested the system and said it was the Alternator...again.
3. Alternator 3 registered 13.9v on install. next day 11.9v but after a few minutes of running jumped back to 13.9. Today drove it to the 4wd place to get an alignment and volts started reading 11.9 again and dropped the entire drive and by the time I got there, it needed to be jumped and charged. The computer test did not indicate PCM issues, but couldn't confirm due to dead battery.
4. Alternator 4 - Picked up new alternator from Napa this time and not Advance. I am nervous to install this one in case there really is a PCM issue that is frying the Alternators. I am really hoping that Advance just has a bad batch and I had really bad luck.

TJW

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skyd

Thanks, this may be a dumb question, but do all JKs have a fusible link? I picked up mine which required a complete rebuild and I do not see a fusible from the Alternator to the battery, but looks like there should be one.

TJW

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skyd

nope, only when the battery voltage was low, I got the typical 2503(Charging System Voltage Low) and P0622 Generator Field F Control Circuit Malfunction

TJW

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