Suddenly no juice

Yep, the 40A Slo-Blow (not fast blow) maxi fuse sounds like a good place to start; it will not blow a few 10's of seconds with amperage in the 50-60 amp range. so should withstand some excess current. But I would find a fusible link for the long term, as it avoids the issues of a fuse and fuse holder in long term, high current uses. Look here: http://www.madelectrical.com/catalog/fusible-link.shtml

And Dorman still sells fusible link wire; it is on the Jegs site. (Gosh, I can surf the web fast! lol)