Hi, long time reader, first time posting. I have a 2015 3500 with the 6.7l Cummins. Shut it off a couple days ago and went to start it this morning. Key FOB would not unlock the truck so I got in the car and bought new batteries. Replaced battery and still didn't work. Manually unlocked door and noticed I had no power at all on the dash or dome lights. Needless to say truck won't start. Put truck on a charger for a few hours and tried again. No luck! I am getting no power to anything in the truck except my under hood light and diagnostics port. (My tuner comes on) any help would be greatly appreciated! Thanks in advance!