Alright. I've only heard one or two other people with a similar problem, and I need some help.

It started a couple months ago when my radio constantly had static. It was the same radio that came with the truck (A 1996, Ram 2500 with a 5.9L V8, (gas)). I thought replacing the stereo would work and at first I thought it did. But after a while I noticed that when I took trips that we're more than 15 mins the radio would just start to fade. When I would start coming to a stop it would get loud again, but when I started going again it would fade. If I was driving for more than 20-25 mins the radio would just go silent no matter if I was going or not. I also noticed that while I was going and it had started to fade I could roll the windows up or down and the volume would increase again and decrease when I let go of the window control..

So next I tried replacing the alternator. Then I tried installing an external voltage regulator (at the recommendation of an O'Reillys employee who had a friend with a similar problem). After that I drove it around for a day and the next day the truck died. (interior and head lights would fade and then truck would sputter and die) then I took the alternator out and had it tested. Came back fine. Then had the battery tested and it came out fine.

So far I've heard two suggestions that I'm still trying to investigate and one is a second ground wire located near one of the tail lights and the other is that the truck my have a built in amp that's somehow messing with the alternator.. Or something to that effect.

Anyone else heard of this problem or have any suggestions?

 

What's the volt gauge in the dash doing while this is going on?

 

As the radio volume decreases, the voltage meter goes down. And when the truck was dying the voltage meter would slowly go down until it got below 8 (the number all the way to the left) and then the truck would sputter for a few seconds and die.

 

Your alternator isn't putting out at that point. Either there is a HUGE draw somewhere, or, the regulator methods you used (including the one in the PCM) weren't working properly. Once the voltage gets down past a certain point, the truck WON'T run...... sensors read really strange when their base voltage gets lower. Confuses the PCM.

Need to find out why your alternator is abandoning ship.

 

Bad ground may cause this also. There's probably 10 or 12 of them.....

 

maybe you got a bad alternator? sounds crazy i know, but i had a alternator one time from autozone, that was bad, they tested it and said it was fine (twice), but then I went back another day, and a different worker swapped it out for me, no problems after that. I think my problem was when the alternator would get hot, something inside of it quit working, sounds similar to your problem

 

Could be a ground issue but with the truck starting and running fine to begin with I'm less inclined to think ground. What kind of external voltage regulator set up are you running? A thread is floating around here that makes mention that if it is not done a certain way the PCM will still try to regulate the voltage. My guess is that if this is happening it could be as simple as correcting the external regulator and all should be good. If the alt is jumping ship as heyyou says then it's doing it for a reason.

 

The external regulator is a gen 1 thing that caused this sort of issue commonly if the regulator was not grounded correctly. Where is mounts to the firewall, fender or where ever, sand off some paint so it goes right to the metal. If not, it will never work right. I have owned 4 gen ones & they all had this exact issue.

 

Still sounds like an alternator problem. Have them swap it with another one.

 

I fought a dying alternator for a couple weeks, it tested fine, twice...