TEXAS-TINO

So I wired up my brothers bmw, put in a pioneer HU and ran power to a 1200 watt amp with 2 12” subs. Now the 1st amp worked for a few months then just turned off, the 2nd and 3rd worked for a week. I checked and double checked all wires and there’re good. He took it to a radio shop and they said it was because his power and ground wires weren’t pure copper, he left with the system working and the next day the amp went into protection mode. Also the amps were blowing fuses, can anyone give me some advice on what the issue may be. Thanks in advance

I'm from Houston,

Well I am amateur at building systems, from Texas. Currently I have a F-250 super cab. I will be installing MTX thounderform box with (2) sundown audio SD-3 10 D4 powered by SAE-1500D. I have 4 kicker CS 6x8 in the doors that I plan on adding a SAX-100.4 V2 to. It's a work in progress so I'll be reading old post asking questions here and there, thanks for the add!!