1996 Dodge Cummins 5.9 Diesel - Crank Sensor Wiring Damage: Symptoms, PCM Risk & Missing at Auto Parts Stores

I recently had a mechanic replace my crank seal on my 1996 Dodge Cummins 5.9L diesel truck. During the repair, he accidentally broke the wires from a small semiconductor component mounted to the frame. This unit, identified as model LM78-05C, appears to be the crankshaft position sensor. After the work, my truck shows no tachometer, speedometer, or odometer readings. The battery is not charging, and the automatic transmission will not shift properly—though the engine starts and runs. One wire from this sensor connects to a fuse in the cab, while the other goes to the crankshaft position sensor. I initially connected the two wires together as a temporary fix, but it had no effect. I have since ordered two replacement LM7805C sensors. My main concerns are: 1. Did I damage the Powertrain Control Module (PCM) or the crank sensor itself? 2. Why don't auto parts stores carry this specific component? The truck started and ran normally before the repair, but now all gauges have failed and the transmission is stuck in a non-shift state. I'm seeking clarity on whether the damage was likely caused by the broken wiring or if it's more probable that the sensor or PCM has been compromised. Any insights into the function of this component and how to properly diagnose or replace it would be greatly appreciated.