Long story short, I tried using a sencond-hand amp from my sister and it was no good, I got a smokeshow in my trunk. Now every amp I try to install doesnt respond. I checked the power wire and ground (hooked them up to the capacitor) they work fine. 3 amps have not responded. Could the first amp that fried have possibly killed the switch in the head unit that we install a rem amp wire for?

 

Okay so I hooked up the rem amp wire to a switch and that worked for a few, but now when the power wire is connected the power LED is on, but as soon as I connect the ground cable it cuts the power. Im confised as hell