I have a 1982 chevy conversion van with a sony head unit. The head unit used to work fine untill one day i noticed a wire was just hanging around. Ever since then my stereo doesnt turn on. A black wire is connected to the head then ends at something that looks like it would connect to something else, then right next to the black wire(connected to the other side of the connector) is a red with black wire that also goes to nothing but is round at the end and looks like it would plug into something. I have no idea where the end of these wires plugs into(im guessing the fuse box but idk where) nor where the red wire goes to.

my interior lights also do not work. this all happened the same time, and there are two other wires(black with a larger connector and a green that is a little larger) that go to nothing.

i have tried many combinations of these 3 wires and the fuse box, but cant seem to get any thing to work.

please help!