Time in Michigan & Hawaii? I bet it's a rust bucket under there. The electrical issues could be related to that along with some water intrusion, perhaps even salt water.
Knowing what I do about these things, I still might not be afraid to look at it but if the bottom is full of rust, it ain't worth messing with in the first place.
If not full of rust, I would just add a battery cutoff switch when not running it and slowly, carefully, methodically begin the gremlin chase process.
'04 Freedom Edition HO & '04 Overland HO (previous '00 Laredo 4.7)