Help! 2000 Durango No crank no start no bus whats wrong?

Help! 2000 Durango No crank no start no bus whats wrong? Why does my 12v light tester light up when i go from battery ground to fuse box ground? Im wondering why i have a no crank,no start on my Durango so i traced all wiring from ignition switch to starter problem seems to be at ground wire from fuse box to alternator i think and i replaced starter relay and it doesnt switch on when i crank it. Also showing No bus please help!