Another molested truck.
The yellow wire looks correct, but I'd check for a splice inside the harness. The yellow wire should provide 12v to coil on start only. more below
The blue wire, and black are suspect.
The blue wire should be sender to gauge, no clue (unless) why it would go to starter.
The black wire has been added(?). Check for voltage on the black wire with ignition on/off. The shop manual shows a W/O purple wire to the same side of the starter solenoid as the yellow wire. I believe the W/O ppl wire is a resistance wire to drop the voltage to the coil when running to 9v. IIRC I've also seen the the resistance wire spliced into the yellow wire in the harness. Hope that helps.
Larry
