O.K., I think some of you are getting confused..... let's straighten this out. Some aftermarket radios have two blue line remote outputs: antenna, which triggers only when tuner is selected, and amplifier, which is on whenever the headunit is turned on to any function. Most aftermarket and factory head units have only one output, and I think DarkInfluence was refering to this. Some people refer to it as an antenna output, because in the old days, before power amps in cars were popular (not trying to date myself) the only remote trigger a radio would have would be the power antenna.