Well I bought the car with an old Sony 510 unit. The front speakers were never hooked up to the unit. So I wired the speakers to the the aftermarket install kit. THe issues is that I get the "beep" from the speakers when I change settings or press any button for that matter. I know the been comes from the speakers due to the cone vibrating at each beep. However, when the radio or CD is in the unit there is no sound whatsoever. Would this be something wrong with the unit and just replace the unit?