FINALLY! Got it done!!!
Found two problems.
1) The turn signal wiring was wrong!
2) Found that a ground strap was left installed some 18+ months, after completing the engine testing and before the cab and other sheet metal was installed. I recall thinking it needed removed, but obviously it wasn’t. That’s what I get for working on this project piecemeal over 10 years and NOT keeping enough notes and remembering to review them!
Lots learned and thanks to everyone that offered useful and constructive help.
The Sparky thanks you as do I.
