I pulled codes today and got the following.
Any advise would be greatly appreciated.
This is what I've gotten so far from reading Shopkey5 about your trucks codes.
P0380 - Glow Plug Circuit Malfunction
- Open or Grounded Circuit, Solenoid Open or Shorted, Failed PCM. Have to get in there and start looking around, a wiring diagram would do wonders to help.
P1105 - Upper Generator Fault Detected
P1106 - Lower Generator Fault Detected
- Possible blown fusible links between batteries and Generator(s) (Alternators), Possible open in power or ground to Generators, Faulty Generator(s) or Faulty PCM
P1747 - EPC Solenoid Circuit Shorted or PCM
This is where your Flashing OD/Off light will be coming from. The Electronic Pressure Control soleniod circuit in the Transmission is shorted to ground or power, or the PCM has gone crazy.
I do know that the plugs for the trannys are crap, and can break and have water enter them and cause issues. I'm still being lazy and haven't replaced mine yet. But it does happen.
So from what I've seen, this seems to be 3 different problems occurring at once. Does it start fine with the glow plugs, charging gauge ok and battery light not on while running, and trans shifts ok?
Without being physically able to see or diagnose your truck in person, I'm kinda suspecting the computer is starting to go crazy. Those 3 things are not too related, but still, it should be looked at by somebody who has access to proper testing techniques.
Hope this gives you some direction!