Help with new HU,amp

[WickerA4]

Hi,have recently changed my concert HU to an aftermarket unit in my 2003 53plate a4.I purchesed the PC9-401 adaptor pluged it all in and pluged the rca cables on the adaptor into the rca connections on back of my HU.But have no sound out of the back speakers at all.Im i right in thinking you need a switched supply to the amp is that why you are giving the blue cable with the adaptor.Would a permanent feed at the amp do for just now or would it drain the battery as i only have the HU on the permanent feed just now until i get round to getting the ignition switch wired up and also i plugged the ariel into the back of the new head unit but am not getting a good reception.but there is one more cable spare that came out of the original HU a small kind of green coulourd push in connection could that have any thing to do with it.have done a few searches but need someone to put me straight as i am an electrician but car electrics baffle the hell out of me any help would be gratefullf appreciated thanks

 

[dualmono21]

the blue wire is "remote turn on"
this powers up the amp when 12 volts is sent down the cable
when it loses 12 volts the amp will shut down

i wouldnt advise connecting the amp to a permanent feed as it will drain the battery

 

[WickerA4]

thanks thats what i thought so ill just make do with no back speakers until i get the ignition wire conected any thoughts on the radio