I have a 01 3.9 6cyl an noticed the guage on the batter drop an stay at 0 an guage light came on..I pulled over a mile away an turned off an restarted it an guage worked again .
I got a code 1682 an reset it an tested amps when driving an its staying at 13.3 or 13.4 even as accelerating.
On a few 1st start ups it still reads 12.8 for a little while..
Is this the Alternator failing or voltage regulator or what ? .
I'm used to it reading a charge right at start up an never saw it be running at no charge for a minute then begin to show 13.4 an stay there as driving.
I'm guessing a slow failing alternator. ?
I put a new battery in 3 weeks ago an its showing a tad bit higher cca an test reading than what is written on the battery .

Thanks

 

Take the alternator in and have it tested. Voltage regulator is part of the PCM.... and are a known problem point.

 

Took it to 2 places an both times it tested as good....any other test to try? . I hope I wont need a pcm.[ voltage regulator]
I'm gonna check the grounds an connect it up secure again..
I might get one off another truck to see if it does the same thing. may be inside brushes ?

 

If it tests good on the test stand, its likely good.

Other option would be to go with an external regulator. Heck of a lot cheaper than replacing the PCM.

 

Thanks ,what's a external regulator look like?
Yes that's a much better option than another pcm.
I took it for a ride an the used replacement alternator did great at 13.9 give or take 13.8 .went to 14 a few times on acceleration. I cleaned the contacts an secured the grounds.
Do some alternators do that as they begin to fail with mixed readings off an on ? .
Could have been the contacts or ground too but I'll leave that junkyard one in it for now to rule out other things.Not sure I want my 1st one on it for now though it tested good off the truck.

 

It's the same regulator Dodge used before they went all computer happy. They used them for years. (decades?) There are a couple threads around here with the process for installing one, complete with wiring diagrams.