I have a 6CD AM/FM radio with data from a 2004 express conversion. Recently the fader part has a mind of its own. When the fader is put to just front, the front speakers work along with the left rear speaker and when put on just rear the rear speakers are on along with the right front. When the fader is centered there are no right speakers front or rear only a slight sound. Can the tech 2 computer tell if its the radio or something . The only thing that has happened recently is the security light came on but the vehicle started. I disconnected the battery. and light has gone off. Thanks for any input