My brother just bought a 1992 Accord i was lookingat it and i noticed the 3rd brake light was dissconnected and there was nothing that lead to a powersourcewhat should i hook it up to and how should i go about doing it?

get a test light they cost under 10 bucks, then have someone press the brake while you see which cable goes to tail taillight brake light. be sure you dont connect it to a signal or to the regular lights, it should only light up when you press the brake. run you wire to the taillights, then just splice into the wire, and wrap it with black tape.

THanx for the info