 You might be able to just swap those two and see what happens. And one of the tests would be swap them and then hit the horn. And when the horn honks, if it doesn't stop honking, that's what's going on. Because some of the relays can, once they close, they stick and they stay on. But if you pull the relay out and disconnect the power, they'll release until they're activated again. Relays, not too expensive, between $10 and $25, depending on what type of relay they are. But that could be everything that's causing your issue right there.