HELP.

I’ve been sitting in my car for over a month With back-and-forth electrical issues, I have replaced the battery, I have replaced the alternator, I’ve replaced the negative battery terminal, I have replaced my sparks and coil packs and front grounding cable. I have checked every single one of my fuses that link to my alternator, I have tested my green alternator cable checking to see if I get my battery voltage to which I did not. I have went through wire diagrams trying to see where my issue might be. I am starting to give up at this point, if anybody can help me that would be amazing I don’t want to junk or get rid of this car over a simple issue. My idea is I might have to replace some sort of wire harness a.k.a. the hole harness leading from the alternator to my coil packs to my ECM. Please please please if anyone knows anything let me know thank you. Also forgot to note, alternator will not charge my battery, biggest thing about this ofc leading to my dash dropping out and dying over and over, where my gauges all suddenly cut and I have no power.