I'd say your problem is 90% a ground and corrosion problem. After all, your boat is 20 yrs old !! Replacing the fuse box doesn't have to be done at Ranger, and I sure wouldn't at $500 !! You can get any new box and just do one wire at a time. Blue Seas makes a nice one. I mounted one on the underside of my front locker lid and ran it just for my Electronics, but it could easily be used as a main fuse block. The really nice thing is, if a fuse is bad, a red light lights and you know which one is bad.