Ouch. I'd try cleaning the plug connectors, then start checking the wires for breaks, or shorts.
A multimeter with audible continuity tester would come in handy.
I don't know off hand what all wiring is bundled together in the harnesses.....but I'd supect a trashed bundle of wires, that maybe got pinched, or cut...or worse.
It's not overcharging, is it? Not sure if the instrument lights would be the first to go if the voltage were too high..
All other lights OK?