Random loss of electrical power?

My stereo would keep cutting out until it no longer worked, checked fuses and relays and all are getting power, check stereo connector and constant prong is fried. I replaced connector and the stereo still won't work but now the dome lights won't work. The key fob won't work on the car, and the door ajar light won't come on unless the car is running. The spot in physical stereo for constant wire is fried. So, I replaced the entire stereo and still no power to anything that stopped working, replacing every single fuse now including BCM fuse, anyone know what might cause this or how I can fix it?