93441 was dropped off for shift lever concern and an intermittent crank/no start concern. The shift lever problem turned out to be the shift cable. After years of fleet duty, the shift cable became frayed and corroded and progressively harder to move. Today was the day that it ceased to move at all. A new shift cable resolved that issue.

The crank/no start was a bit more involved. The fact that it was described as "intermittent" presented its own unique set of challenges, the biggest of which was duplicating the concern. I wasn't able to duplicate it at that moment. But I did notice a couple of red flags during my diagnosis.

The large rectangular white box seen in the photo above is the ignition switch. When the ignition key is turned, the starter is engaged via linkage within the steering column that completes the starter electrical circuit. The glob of electrical tape wrapped around the red wire means that someone tried to repair something by tapping into power directly from the ignition switch. So the next question was to find where the added wire goes.

The added black wire was fed through the bulkhead and spliced into the ignition coil, hence the second glob of electrical tape. Unhooking the added black wire resulted in a crank/no start. So now I'm dealing with a problem that someone tried to (poorly) fix. Rather than repair the added mess, I pulled up the truck wiring diagram to figure out what was trying to be fixed in the first place.

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.