It seems that we can not reply to your original post. so here is my reply.
"Take the cover off and look at the ground to the buzzer/alarm. I have seen them just have a lose/corroded connection that would cause the issue your having. It might not have acted up for them after being throw around during shipping it. Also check all your connections on the tractor. The alarm draws more amps than the lights do. So if your limiting the amperage it would make it act funny too. I have had this happen on the early JD 7000 monitors."
"Take the cover off and look at the ground to the buzzer/alarm. I have seen them just have a lose/corroded connection that would cause the issue your having. It might not have acted up for them after being throw around during shipping it. Also check all your connections on the tractor. The alarm draws more amps than the lights do. So if your limiting the amperage it would make it act funny too. I have had this happen on the early JD 7000 monitors."