According to the wiring diagram, turning the ignition key to the start or run position feeds power from the ignition switch to one of the terminals on the ignition coil connector. With the black wire disconnected, I did not have power at the ignition coil. This usually points to a wiring problem within the vehicle wiring harness, and someone overlayed a wire in an attempt to bypass whatever issues is present. Technically, this repair is correct. But this is definitely not how a wiring repair is made !
I traced the circuit in question and discovered the approximate location of the broken wire within the harness. Rather than tearing the wiring harness apart, I overlayed a wire and bypassed where I thought the problem was located. Using proper butt connectors and double-wall insulated heat shrink tubing repaired the problem correctly.