Somewhere there is probably a main fuse. Maybe under the hood.
Unfortunately there is an old saying that says if i could diagnose a car over the phone/computer I'd be rich. It could be any number of problems Alternator, ecu, pcm, wiring harness, and about 10 other things best thing you could do is get a voltmeter and a test light and start checking electrical systems seeing if you are getting any current flow.
bad connection/by the way/how did you know the batt is good if nothing works??yank the batt out and check the cables/if the batt is 3yrs old replace it
