electrical problem

[kenb]

I bought a 96 Cherokee Classic for my daughter and after a few minor repairs it was running and drivable. she has been driving it for about 3 months now and it has bee great until the last couple of days. She said that she is driving and all gauges drop and the engine quits. I towed it home and checked it out pulled fuses from underhood and found none bad. found ground cable loose and tightened it and it started and ran again. Next day she was on way to work and same thing happened again I checked and lights worked radio work and ect. I then opened hood and pulled 60 amp fuse and put it back in hearing it connect (sparking noise) told her to try it and it started and she was off. any clue why this is happening or cause.