Help! New faulty alternator caused problems?

[Kgardner350]

Hey everyone about two weeks ago I purchased a 2000 ram 2500 5.9 with a 47re. 

It had a stumble at idle but never left me stranded in the two weeks driving it. I was reading about possible alternator noise causing problems so I replaced it with a remanned alternator. The new alternator went up in smoke had a short in it somewhere is my best guess. So I switched the old alternator back into the truck since it was still charging atleast.

I got started driving maybe a mile or so and my alternator gauge needle went to the bottom and the cluster said check gauges. I pulled over for a sec to check the plug on the alternator. Got back in started moving and the gauges did some wierd stuff and the truck pulled over chugged a few times and died. Now I have no reading from the tps, cam sensor, or tach. 

 

Any help is huge right now guys this is my transportation for work and I could really use some advice.

[Mopar1973Man]

Sorry to hear this. But my first thing to do is pull the alternator have it tested instantly. If it fails replace it. Then pull the ECM and send it out and have it tested and repaired. This is not something you can just do in a few hours so I'm going have to say you going to need to find a loaner for a while.

Edited October 20, 2021 by Mopar1973Man

[Kgardner350]

Thanks I will look into finding someone that can test the ecm.

I put the old alternator on the truck for now cause I know it ran consistently. This morning I came back to the shop where the truck sat overnight and I tried to start it just for the sake of it and it started right up with no issues. I did find the alternator fuse blown so the truck isn't charging. How finicky are these trucks with voltage ? I'm trying to make sure the problems weren't just the result of low voltage from the lack of alternator input. It only made it a mile down the road and the batteries still had 12v afterwards and turned over strong?

Thanks for the quick response !

[Mopar1973Man]

Ok. So you might have electrical issues being it started. It also could be too high fuel pressure that created the hard start later.

Edited October 20, 2021 by Mopar1973Man

[JAG1]

You have to get alternators on a test stand before installing. They aren't very trustworthy so especially test for AC ripple/ noise. If they cannot test for that you should go somewhere else to a place that can and aklso understands what that is. Has to be lower than .05 Also if your lift pump is running off the ECM there is a chance of frying the ECM. Your supposed to let the ECM trigger a relay so the lift pump runs off the batteries. I had 2 alts short out and get hot within 6 mos. Now I got one that seems to work fine. I also cleaned grounds everywhere, engine block, etc. and basically put the electrical system in top shape. It's very important. And that factory alternator grounding thru the mounting bracket is a corrosive culprit too. Got to clean the bolt everything about it. I run an independant ground.

 

See article about W-T's really great write up on these trucks. He did us all a great favor.

[Kgardner350]

Just to follow up. I replaced the alternator with another new one and is charging no problem. As for the problem with the truck not starting it seemed that there was another issue I wasn't aware of that the crank position sensor was bad and would stop working sometimes when the engine would heat up. When I would go back in the morning the truck would start as normal. When the problem would occur I noticed the tach would not move when trying to start the truck. A new ckp sensor and problem solved. Thanks for the help.