2016 Pete 389 interior/cecu problems

[indian_richard]

2016 Pete 389 w/ cummins

I noticed that my cab is not grounded by using my power probe. So I started checking grounds and I noticed that the cab, frame and starter grounds all show 0.25 volts. The batteries all show good ground, but when I turn the key off and close the doors, once the interior lights turn off they all show good ground. Also, a select half dozen or so gauges and switches have backlights on at all times. Unless batteries are disconnected of course. The backlights have been like this for almost two years now since we owned the truck. The grounding/voltage scenario just started this week.

Any help is appreciated. TIA