Hi, I'm new to the world of internet mechanicing but I need some help. I just put new batteries and cable ends on today. (In a rainstorm in a parking lot) When I drove off I noticed that my volt meter was reading low. I went back to get the batteries tested and when I popped the hood one of the batteries was boiling over so I assumed that it was overcharging. An alternator guy told me that if it was overcharging it was the voltage regulator which in my 06 5.9L Cummins was in the ECM. He thought that it would be around 400 bucks to fix that. Option 2 was to put an external regulator on the alternator for 60 but he didn't know what that would do long term to the computer. What should I do or are there any other things that might be the problem? We are a one vehicle family, so fast and cheap solutions are good.

 

Welcome to DF. Will move you to the correct section.

For future reference:
https://dodgeforum.com/forum/dodge-r...ead-first.html

 

fast and cheap solutions won't get it

 

External voltage regulator will cost less than $30, get one off a 70s/80s Dodge.

But you'll have annoying lights on the dash to contend with.

I know you said you put two batteries in, but get them load tested. They need to be pretty close to equal. There is a temp sensor under the driver's battery to prevent over charging, but it only monitors that one battery. Make sure that's working, and make sure you're getting good contact with both batteries.