Hey mudshiner,
Unfortunately, furry little rodents can cause all kinds of trouble. Everything from sunflower seeds in the intake to a whole nest of prickly pear cactus under the hood. OR dead mouse odors when you run the fan inside the cab, eminating from half a mouse inside the blower unit. (I still don't know where the other half is). Or, as you found out, they can take a snack of wire insulation and leave you chasing electrical gremlins.
I recommend that you take a multimeter and begin hunting down wires that are grounded and shouldn't be. I'm guessing your guest chewed some insulation off some wire and opened up the possibility of said wire touching ground and shorting out the alternator. Which, I think, would ruin it and/or the voltage regulator. Do not neglect either the possibility that the wire causing the voltage light to light has been shorted to ground. The part about the big mudhole make me think a wire moved and made contact somewhere.
Best of luck, and keep us updated.
