Ford E450 6.0 Powerstroke - No Crank, No Start
I'm having a bit of an issue with my rig regarding starting. Here's what happened that I know of:
Over the summer I drove to PEI from my hometown (about 350 km) as the first medium distance test trip for my conversion. Right before I got there I experienced some weirdness with the transmission and the speedometer acting wonky. The ABS light had been on before this trip but I attributed it to something minor initially so I didn't bother troubleshooting
The bus has started, ran, and drove plenty of times in between then and now but yesterday I drove it and the speed sensor (which I figured was already semi-faulty) must have finally failed as the speedometer dropped to 0 and the transmission remained in first gear. This problem was confirmed by a code reader.
When I returned home, I parked the bus and thought nothing of it besides the fact that I'd have to replace the sensor and that would be the end of it. Now when I go to start it, all I hear is a "click" (normal sound). The engine does NOT turn over at all.
My dad hooked up some device I'm not familiar to the starter underneath which acts as a ignition and bypasses the starter relay. Using this method starts the engine successfully so the starter is fine as far as we know.
Does anyone know why this might be happening? Is it possible that the ABS light / speed sensor failure would cause the starter "circuit" to be interrupted?
Thank you in advance.