No power in a s13 sr swapped

[J.dover08]

Ok I took my buddy for a ride in my 240 and got back shut it off about 10 minutes later I started it back up and it ran for about 30 seconds the just died like the battery went bout 15 seconds later my egi relay started buzzing. And I have no power to the inside of my car except the oil light and battery cmon like usual. I have no power to the ecu or fusebox inside the vehicle on the outside my alt fuse was blown and ret motor was blown I'm not good with wiring at all but I kno how to do It. Just wanted to get some ideas on what could be wrong. The battery is fine and my terminals are new so any suggestions?

[kamilp1908]

Check alternator grounding, maybe cable broke down.