best buy would not install my radio(under their free installation)because there is no factory harness. i hooked it all up (correctly) and i'm still getting no sound from my factory speakers. it's not a prob with the radio cause i tested it. i called thier installation dept. and he said i had to turn on the factory amplifier.(don't have infinity system). where is it and how do i do it. I do have sound but it's cause i hooked up some highs to my amp so at least i have something to listen to.