Crazy old 87 honda leaves the radio on

So lately I've noticed that my 87 honda always has a dead
battery every week, I just thought that someone forgot
to turn the radio off, but today I discovered that when you turn off
the ignition, sometimes the radio is still left on .

Weird problem to have, especially since its the first thing that
has ever gone wrong with the car.

 

There is a wire that goes the the radio, sometimes called the ACC wire.
It's job is to tell the radio when the key is in the ACC or ON position. If
there was a problem with this wire, or somehow related to the circuitry of
that wire, then the radio might always think the car is on.

 

either the radio is hooked up wrong, or theres something funny going on with
the cars electrical system