I have an '82 with an aftermarket head unit (sony xpload, I don't remember the specific model number). Anyways, every time the car is turned off all of the setting on the head unit gets reset. I'm not sure this is relevant, but the head unit is not wired directly to the back of the fuse panel, it is underneath the fuse where it should be wired into. The previous head unit was done the same way and nothing like this ever happened. Any ideas?

 

You sure the 12v constant (battery) is getting power? I suspect the unit is getting only power via the ignition/accessory line giving you this noticeable issue. Likely it's in-line fuse or the fuse used by the harness for that line.