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.