also check servo and connection. horn and cruise circuits go through the speed control servo. these trucks have a recall about brake fluid leaking at de-activation switch on master cyl. that fluid travels down through the wiring and causes shorts. i have seen many leaking switches and few affecting the servo. the servo is right beside the air filter box on rear side. most of the time the clock spring fails you will see the air bag light flashing too.

 

Thanks for the info.