I am in the middle of connecting my wiring harness and my reciever together.... and i am going to put the power conector wire in (the one that goes from an amp to the headunit) Do i connect that to the ignition switch wire (red).... This used to be hooked up in another car and the p. con wire from the amp was hooked up into the power antena wire from the headunit. Is that ok also?... and which one is better to use?