Detroit 12.7L Turbo Sporadic/intermittent Working-Not Working

Hi all, I’m having issues diagnosing a turbo problem with my 1999 Detroit Series 60 12.7L engine. Here’s the full backstory:

Every time the truck drives through a bigger puddle of water on the drivers side, something gets wet, and the truck just shuts off. Another issue that occurs with that is that the cruise control won’t work, not while trying to drive to pull it off the road or while stationary. Truck will re-start, but cruise won’t wo I and it’ll shut off after 20-30 sec. Once the truck dries off (I’m assuming that’s the reason), it works just fine, it typically takes 45 min to an hour of sitting it out. Here’s the kicker:

About 4 months ago I ran through a bigger puddle, and after drying out, my turbo and a couple of gauges started acting up. Turbo randomly kicks in and out, sometimes to full power, sometimes it just stays below 15psi. It’ll happen instantly, like the engine gets jerked as the turbo kicks in and out. That lasted about 2 days, and afterwards I’ve never had an issue with it until 5 days ago. Now I’m having the same issue, but this time it doesn’t seem like it’s going away.
Does anyone know what could possibly cause this, or where to look for? My assumption is either the ECM or some other harness is toasted, but I really don’t know too much to even look. All I know is that I have no power, and can barely go up the hill empty. Any help is highly appreciated.

 

Here’s the link to the video. Sorry for bad quality but I can only replicate the issue while driving.
Studio Project - Kapwing