I'm wondering if anyone else has encountered this issue - my stock radio is stuck with the security system/light on and no amount of fiddling with the buttons, code, or battery seems to reset it. It comes on with power but no audio or anything from the little display screen. Is there some stupid security fuse I can try pulling?

 

you have to put the right code in. Done this many times when battery has gone down or been disconnected.
Also it will only let you fiddle with the buttons a few times then it will not accept any code for an hour or so.