On that radio the two wires coming out the side are power leads. One is for the radio power which can be wired to the battery or the ignition switch, and the other is for the dial lamp which is wired to the headlight switch- this way the radio dial lamp dims with the rest of the illumination. The speaker lead is either directly on top or bottom (forget on this model) sometimes there's an RCA jack there and other times it is just a plug that a pin lead slides into.
