Friend is having problem with interconnecting alarms,all alarms are connected with ac power but they only go off individually she would like them to go off all together,When she presses the test button the one she presses goes off only,they are all interconnected with 14 3 wire with red connected to the smoke alarms yellow interconnecting wire the red wire was powered,then she found out the red wire did not have to be powered because it should be isolated for battery back up usage so she says.So she stopped power going into the red wire and it still does not work the way she wants.The smoke alarms still do not go off all together when the test button is pressed.What does she need to do?