Need help with 5.9L 24V Cummins

[Paul Cataldo]

2004 Dodge 5.9L 24V Cummins. Just got this truck. Used. Its a nice truck but needs help.
"CHECK GAUGES" light comes on and battery voltage needle drops to far left/zero.
Without getting too technical here, I've read its somewhat common. Could be alternator but I dont think so as I'm getting 12.5v at each brand new battery but dash needle reads ZERO volts. It could be grid heaters or relays or even a simple ground issue.
I know enough to be dangerous, and that is it.
I'm in need of a good diesel guy, even someone who possibly does this work on the side. I cant take it to Dodge. They'd probably kilI me.
I do have cash to pay someone who really knows these trucks and can help a guy out in a bind. I live in Fayette Co.
Hope this was ok to post here. Really needing some help here guys. Its probably simple, but not sure.
Does anyone know who is the man as far as Cummins repair goes?
I know you guys know some people!
Thanks guys.

 

[transfixer]

If you're getting 12.5 volts at each battery with the engine running, then your alternator isn't putting out, with engine running you should have close to 13.8 volts,

 

[lonewolf247]

Take it to autozone, or a similar auto parts store and have them test the alternator. Most of those type stores will check it for free. It may be that simple. Check that, and go from there.

 

[little rascal]

Tractor service depot on Fulton Ind. Blvd. They work on mostly big rigs, but all kinds of diesels. There's a guy who they hired for 100k a year. He's an electrical wizard. The wife works there, she used to work for Kenworth. Everybody that used to go to Kenworth goes there now.