Thanks Michael & Hansen. That is good information. I've had poor luck locating accurate wiring diagrams in the past. Any recommendations on a source?
These wires in question are not folded back. They appear to have been cut and something removed. The truck was "inoperable" and purchased in auction. It was from a mining operation in AZ and they robbed some parts off of it during the last year they had it and it was abandoned for some reason. I'm certainly no wiring technician, but it did occur to me in hindsight that when I was taking the dash apart that I did not remember removing an OBD port, and on checking, it was indeed missing - however the only one I saw online appeared to have 6 wires and the bundle that is suspected to have been the OBD connector on my harness has 8. My rebuilder currently suspects the other 4 orange based wires from a different bundled lead may be from something like trailer brakes. I agree a good wiring diagram would be helpful if I can get my hands on one.