Resolved. I have a scangauge code Cummins doesn't recognize.

You might try somehting like dielectric (non-conductive) grease on the posts after tightening.

True story: Used to have a car that would start sometimes, and sometimes if you tried to restart it (Say after buying gasoline) no joy.

Turns out the alternator casing was not properly grounded, That's right, those big well greased bolts were not making contact,, I removed one slipped a star washer under it and all was good.