I solved the problem with a bit of help from Newell. I have the correct red/black twisted pair wire, but it was wired into the RV-C connector front pins (towards the front of the vehicle), but they needed to be in the back pins (towards the back of the vehicle). The photo shows the correct wiring. Once I did that the Volts/Amps/Power Source display worked again.
Mick & Renee
2009 Newell 45’ 8” #1277, C15 625HP 12-speed ZF
Full time working and traveling.