Hello. I am installing an amp in my 1999 Mustang. I am using the factory head unit so I already bought a line converter (to get the required RCA cables). My question is where can I install the remote wire to turn the amp on/off? I checked all of my fuses with a test light and every single one lights up with the key off. I need a fuse that only lights up with the key on and with the key backwards to wire the remote wire to. In other words, I need a wire to tap in to that only is active when the key is on or backwards. I am thinking the cigarette lighter? Can someone please help?