I need y'alls help

[Fire_boy3]

Hey y'all I need some help. I got a 65 gmc c10 that had a 350 from a 84 c10 dropped in it. Well about a week ago I went to leave my buddies it wouldn't start so I jumped it then the next morning it happened to me again so I got a new battery hoping that would fix it. Well it didn't so I took it to get the alternator tested and it wasn't charging enough so I got it replaced and put a new one in it worked for like a day and it happened again so I got that one tested and it didn't work so I replaced it and put the current one in. I got it tested that day and it's working charging at 12.6. But earlier tonight I went to start and lo and behold the battery was dead. So it's not the battery or the alternator so I must have something draining the battery well the day before the problem started I started having issues with my right turn signal and break light (my grandpa added another break light to each side) so I got down there and found a bare wire taped it up but that didn't fix it. Also about 3 days ago I turned a corner and my radio quit working so earlier tonight I checked the fuse box (non original fuse box) and found the radio fuse melted. Could that melted fuse cause the battery drain and do y'all have any idea what could be causing the problems with the break light and turn signal? Could the turn signal and break lights be what's causing it? Me and my grandpa have done everything we can think of to fix the issues but nothing worked. Sorry for the wall of text but I'm just at a loss right now.