basically the +12v supply, should be the only wire with power on with nothing else connected goes to the battery terminal BATT+
ST is the starter solenoid wire
ACC, generally the point of supply for radios, lights etc
IGN power supply for the coil, points, electronic ignition supply, generator excitation light.
to prove a point use a multimeter to confirm the solenoid wire to starter and leave it off
rotate the key around to acc position, usually clockwise one position from putting the key in and test for volts at the electronics supply
rotate to start position and hold, you should have power to the starter terminal, wont start as you have it unplugged!
back to off (key out) only power on the BATT+
rotate counterclockwise and only power on acc but not anything else.
should be able to plug back in the starter solenoid and attempt to start!