Audio Systems: Subwoofer Feedback, line output converter, fuse box

Question
Scott, I had a question regarding car audio.  I have a 2000 Cadillac Deville with factory radio.  I have a line output converter hooked up to the factory subwoofer speaker wire to convert them into patch cable jacks. That is connected to my amp.  I have a switch from the remote wire on the amp to the ignition in the fuse box.  Everything seems to be hooked up properly, but evidently this is not the case.  My dilemma is, when my vehicle is RUNNING and my radio is OFF, if I turn my amplifier ON (via the switch) I get a constant feedback from the subwoofers, just like if it were hitting a deep bass note, just as loud as if I had my volume turned up and it hits a deep note, and it stays on until I flip the switch off.  If my radio is ON and I turn the switch on the subwoofers operate properly.  Any help would be greatly appreciated.

Thank You,
Jeff

Answer
"I have a line output converter hooked up to the factory subwoofer speaker wire" may be the problem. If the LOC is connected to the factory amp, you run into problems like this.

You need a factory bypass harness to the LOC for it to work correctly. You can get one from here http://www.metraonline.com