it will not do you any good in this situation. The stock mach system uses a 6v remote turn on and you will need at least 9v to switch your amps on. Check the harness with a voltmeter to find the +12 ignition and use that to turn the amp on/off.
I just wired it into the fuse. Its acting screwy as hell though. Sometimes the audio doesn't come through the speakers. Not getting to the amp. I think its something to do with this line out converter i'm using. Not too sure. Amp doesn't go into protect mode or anything. I'm stumped.
you hook it up to the accessory fuse which is easiest, and the audio dont come through the speakers sometimes could be the audio input/rca wires, or speaker wire somewhere