first off - howdy guys. Haven't been on much - havent really been modding much or having problems.

So let me preface this by saying this truck has dual 110 amp alternators. Had to replace the batteries recently, and I'd just turned 200,000 miles so it was time to check. Both alternators failed on the bench so I replaced them both.

I have an aftermarket volt meter in my gauges as well, and it was starting to jump up into the red (14+) volts in the morning. It only did it intermittently. After a week or so, it was getting worse, so I swapped the alternator.

Fast forward a month, it started doing it again. This time it PEGGED the aftermarket and OEM volt meters. One early morning it did it so bad it blew out all my headlights !!!!

I took the top alt back in and it failed the test, so I replaced it again.

This morning while driving home, I noticed it jumping up a little bit again into the "yellow" area on my voltmeter showing a slight overcharge. This is a brand new alternator, brand new batteries.

Is there something else in control of the voltage / output that could be failing ????

 

I once had a car which exhibited the same problem...changed the dang alternator and burned up a battery due to it. Did the same thing again, but this time I started looking for another problem (other than the alternator & battery). It turned out to be a bad ground between the body and battery. I can't believe you would have found four alternators with bad voltage regulators...

 

My thoughts too, ground(s)

 

I've checked the grounds .. they're as tight as possible.

What else could it be. Now what I have noticed is this is only in the morning after it's sat overnight, and with my headlights on. Later on in the day there's no problem ... I'm beating my head on the wall with this one...

 

Subcribing.
I would take it to an alternator shop and have them check the system and tell them the history. Stay and watch. Chet

 

Tight doesn't mean its good. Run a 6 or 8 guage ground wire from the alt mount up to the batt Neg.

Barney