Ford F650 V10 gas engine

OBD2 was Automotive based for gasoline
Engines initially, i seriously doubt a IH dealer that does not sell a production gasoline engine since IH discontinued their production/use by mid 1980s in medium duty machines would have OBD2 equipment.

I contacted the sales rep for some popular software system sometimes mentioned on this forum and the rep indicated there was indeed some form of gizmo for around $8k that could handle the Ford 650 Gasser.

I dreamed up the idea to determine if Snap On could furnish this type of test and repair instrument and if so, who locally would have bought this type of tooling .... and bingo! got one place that also did mobile mechanic.

Said tool apparently was big dollar - but it reloaded some file and did some scans etc and then he started up the truck and it continued the analysis etc and then the light was cleared.
FIXED and now have the mechanic shop pretty local - no need to go 100 miles for a dealer.

Many thanks!

Wow. Good news and thanks for the update. All your footwork paid off.