Are the wires connected properly (as shown below) to the horn relay spades? The green wire is 12V out to the horns, the black wire is the ground for the horn relay (from the horn button), and the pink/black wire is from the key minder switch in the steering column (switch is closed if the key is in the ignition). If the key isn't in the ignition, the buzzer shouldn't work; if it does, the key minder switch has failed closed.