You have a tough one there John, my mind keeps coming back to the fuse box or a bad main connection at some point like the ground. Have you unplugged all the main harness connectors and looked for corrosion or burned/broken pins? I would want to come see for myself but you are a might far for me to drive.
I learned all I need to know about life by killing smart people and eating their brains. Eat right ,Exercise ,Stay fit, Die Anyway!