Verifying connection points Bob.
A = front terminal of fender solenoid/battery (+) from trunk/auxiliary fuse panel
B = rear terminal of fender solenoid
C = PMGR starter terminal and jumper to PMGR solenoid (negative side).
I looked at my Motorcraft PMGR starter from my 92 Mustang.
This solenoid on this starter has “ground side” connected to terminal “C” not to chassis ground.