Help with cruise control

[marmon]

I just picked up a 2001 Ex and it has a train horn hooked up. It's hooked to the regular horn and has a switch under the dash that will let me switch from the regular horn to the train horn using the steering wheel factory buttons. Problem is that when I push the "on" button for my cruise control it also blows which ever horn the switch is set to. Ant ideas on how to get the cruise back working? Thanks