Help please. On the side of the road - electrical issue w/ codes

Truck starts and idles fine and the accelerator pedal works normal while sitting in neutral. When I start driving I get check engine and loose almost all power. It feels like a derate mode.

The codes are below. Any advice is appreciated.

FMI=5 - Current Below Normal Or Open Circuit.
SPN 558 Accelerator Pedal 1 Low Idle Switch.
FM1=4 - Voltage Below Normal or Shorted to Low Source
SPN 3509 Sensor Supply Voltage 1

 

Now while sitting for a bit and after doing a reboot I have the below code.

FMI=2 - Data Erratic. Intermittent or Incorrect
SPN 639
FMI=4 - Voltage Below Normal, or Shorted to Low Source
SPN 3508 Sensor supply voltage 1

 

And the fun part, I may be outvof phone service in a few miles. It's always an adventure.

 

I cleaned the battery terminals. I'm on the road. So far so good.

 

Not sure. I cleaned the battery terminals and I did find one small wire going to the starter that had a rub in it. I taped it up.
10 miles on, so far so good.