Don't bother with a salvage yard harness, go straight to the local Cat dealer if it needs one. Wiring on anything almost 20 years old is going to be no better than what you have now.
Do you think I can drive the truck before fixing this code? I'm working on getting it and the trailer inspected now and it would be nice to be able to drive it around town. Just trying to gauge the severity of the code. Thanks!
Just an update to close out this post. The sensor I posted pictures of earlier was in fact the crankshaft sensor. I found one of my wires going to the connector was totally cut but the insulation was barely hanging on it and made it look like it was still connected. I had enough room to repair the wiring. I let the truck idle for 30 minutes and the code reader did not pick up the code. I'll keep monitoring it but I'm pretty sure I'm all set.