Thanks for posting the corrected wiring J , I am always hesitant to post when I don't have the exact year, especially on the first gens, seems like they had 4 separate variations in 5 years ( 89-93 ).........

I am still thinking he has a bad solenoid, but with the wiring diagram, it shouldn't take long to diagnose.

 

Thanks guys,

I hadn't had the time or weather combination to crawl under the truck, until today. J Martin, you're right, I need a new tranny shop. The tranny wiring harness is all covered in grease & grime, but it's plain as day that someone (PO?) has suitcase spliced into both wires that go to the OD solenoid. I should have spotted that when I bought the truck, but truthfully, the PO was a ham radio guy, and this truck had antennas and lights and air horns on it, and has leftover wires going every which way, so I didn't pay much attention... I should have.

Regardless, the splices look old and suspiciously loose, the wires are all wet and oily, I will have to get back under there when I don't have a toddler tugging at me (ie., not today), and test the voltage, resistance of the solenoid, etc... and clean things up... but I think it's obvious someone has tried to troubleshoot / override this OD before...

I didn't realize these failures / codes were discreet issues and not a cascading failure... I do now. Thanks.

-N.