The 8W-10-10 circuit comes from the 200 amp fuse directly to the ignition switch.
With the clutch interlock activated, power is applied directly to the pulse module on pin 1B.
The pulse module should then supply 12v from pin 1F to the starter solenoid for a preset number of seconds.
The 12v to the PTCM is to notify it that an engine start is in progress, do it's thing and figure out engine timing from the Crankshaft Position Sensor and the Camshaft Position Sensor, then supply spark and fuel at the appropriate times.

If you are not seeing 12v at pin 1B on the pulse module when the ignition key is turned to start, then you have a bad ignition switch, or a broken wire. If you are seeing 12v at 1B, but not at 1F, then you have a bad pulse module.