I'm assuming he has an aftermarket radio. Think he means the remote wire that goes from the radio to the amp is not getting enough power to turn the amp on.
It only takes a couple volts to switch on an amp, if this seems like an issue I would look into some other things cause the deck not putting out enough power to turn on your amp is not the case.
we need more info, what equipment do you have? The stock stereo uses a 6v turn on rather then a 12v so that is the only thing I can think of. The remote turn on is just a 12v, low current signal that does nothing more then turn on a relay to allow the amps to draw power from the main power wire.