KW T2000 Electrical Gremlins

With the engine issues solved I've started working on getting the electrical issues sorted. There aren't too many but they require a deep dive as my basic rummaging around has yielded limited results.

1. Cabin wiring dead short, the PO seemed to have the same conclusion and tore most of the interior out trying to find it. It's killed two alternators so far by pulling the batteries low while driving and overheating the alternators. Disconnecting what I believe is the cabin ground gets rid of the short but the truck won't function with that removed.
2. Reverse lights refuse to work.
3. Gauge panel gauges are permanently stuck doing sweeps, previously they wouldn't power on at all. Found a white wire that was switched power, key on, that was going to a 5V regulator on the board, there was also a red wire that was going to a 12v regulator but it wasn't getting any power. Jumped the terminals and the panel came to life, removed the jumper and it still works. It's a 97, so its pre CECU era electronics.

The local dealership is refusing to supply any diagrams of any sort, and I can't find any online for the T2000 with an N14. I've thought of tracing and making my own diagrams, but that leaves a lot of room for error and I don't want to risk the electronics in this truck as the dealership charges a pretty penny.

 

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Holy crap lol, thank you so much. The truck looks like it's going to be parked for a month or two, state inspection turned up more issues than we thought it would and most of them are electrical.

The interior is a cluster, but theres an issue with the dash power supply that kind of makes sense and might explain the dead short at the same time.

Reverse light looks like its the reverse switch on the trans, I'm getting power on its feed and nothing out so that seems solved for now.

I've been digging through the schematics and it appears I'm somehow getting 12 volts on the ground line both dashes and the line that should be supplying power is dead. Pretty weird considering the dash works perfectly.