I am trying to install an Alpine CD player in my 92 Lexus ES300 and am having some problems. I got the dash kit and the wiring harness. Everything was pretty easy to install, but when I tried to test the stereo before putting everything back together it didn't work. The stereo powers on and the functions seem to work, but I don't get any sound. Is there a factory amp on the 92 that has to be disabled? I'd appreciate any help.