Originally Posted by Doogiept
So if I understand correctly, is it that when the key is turned on the output level is too high for the sub and it kicks out but when the harness is disconnected and then plugged back in this doesn't happen? My brain needs to make sense of this or I won't sleep !!
It is true than when you run into problems you learn more. Thanks for the help
No, that is not what happens. When the Tube is connected, and the vehicles system is turned on, the audio system is sensing an impedance issue with the subwoofer. As such, the system intially turns on, and then off, which is why no music plays. However, by unplugging the Tube, then turning the system on and plugging the Tube back in, the Tube starts playing (if I am following correctly). This is all indicative of the sensing circuit of the amplifier "seeing" an impedance issue, thus preventing playing or start up.