Need some wiring help

[Jon17]

So I know nothing when it comes to wiring and I am trying to figure out what the unit circled in the big red circle is for. The wires that run up from it circled in the smaller red circle are cut. Seems like the last owner was messing with the wiring..



On top of that I had a wire running straight from my battery, with a joint to a 30 fuse then to an on/off switch under my steering wheel then straight back to the driver said taillight. Ever since i took out that wire from the battery to the taillight the passenger side turn signal stays on constantly. Certain things in the dash like the different vent buttons do not work its stuck on the windshield setting (not due to the weird wire removal) I guess an FSM is in order.. Any advice is appreciated.