Well, the rig is back running. The problem this time was that the wire to the solenoid had fallen off. Unfortunately the solution was difficult as the eventual diagnosis was easy.

The starter is so buried on this rig that I had to take the starter back out to reconnect that wire. I spent over an hour trying to reconnect the wire without removing the starter. Even to attempt that I have to remove the collector pipe. Perhaps the smallest of Randy's dwarfs could have done it, but I couldn't.

The solenoid connection is simply a push-on connector.

I found a place to attach the multi-lead ground wire and that was almost as painful as the starter wire. It had to be a relatively small bolt to fit through the crimped on fitting on the wires. I finally found a correct size
bolt holding a wire loom on the bottom of the pan that locates the wires running to my favorite part of the engine - the starter. Even my Gear Wrench could barely get it off.

By the way, if my wife ever has the good sense to give up on me, I am going to find the inventor of the Gear Wrench, and marry them, regardless of their gender.

I did pull the main fuse panel loose and none of the wire patterns matched the documentation above.

We will see if the truck runs appreciably better with the ECM properly grounded.