We tried the cassette adapter, bought a Belkin adapter. Don't ask me to explain this as frankly I can't. This goes against everything that should be "right" When we put the tape adapter in, the left front channel drops out and only the left front. When we put a regular tape in, or listen to the radio all the speakers work fine.
There should be no way for the head unit to distinguish front to rear. If the entire left side or entire right side went out, that would be understandable, but just the left front? I am going to pick up a good quality FM adapter and try that. It won't be as good as a hard line wired adapter, but it will make do for now.
