Lets take it step by step to the major decision making points for determining if the vehicle is worth the re-investment. I broke it down into 4 sections to help you put minimal time and money into the machine.
Disconnect batteries
Drain all fluids and I mean ALL fluids.
Open turbo intake and exhaust, and other systems to let water dissipate. If in doubt open a line and inspect contents. **Check weather before opening anything**
Attempt to rotate engine by hand to ensure no hydro lock. If hydro lock - STOP! Reassess engine for water intrusion. No hydro-lick - proceed.
Start tracing from the batteries looking for corrosion. Tend to it as discovered.
Install batteries and ohm out systems as needed.
Check for electrical power to systems and if computers are "happy" - DO NOT CRANK ENGINE!
If no power to systems then evaluate for potential cost of repairs vs value of vehicle.
Fill with the intent to flush transmission/transfer case and engine with 10w. **Best to do so after old fluids have stopped dripping into catch pan.**
If you feel the need to use an alternate fuel container for testing then do it.
Assess to see if it starts, runs, then transmission engages in gear. - If major electrical problems persist then put a 12v wire on the injection pump shut off solenoid from the battery and jump the starter at the starter relay (right of the power steering reservoir facing the engine - 2 larger threaded posts covered in silicone). If engine runs - continue electrical evaluation. If engine does not run - investigate lack of fuel prime, fluid contamination, or internal mechanical damage from water intrusion.
From there you'll be disconnecting brake lines to remove trapped moisture and moving on to electrical sub system tests that could go on for ages.. or not!
