I have a 1998 chevrolet suburban with a clicking noise under the dash and the horn beeps at same time and rate as clicking noise. Replaced turn flasher but no joy. Slowly moved turn signal up no joy. Slowly moved turn signal down no clicking noise but horn continues to beep. When driving clicking continues and horn stops. Regardless if parked or driving the exterior lights work correct and don't do anything abnormal.

 

Welcome to the forum.

Is there a relay in the horn circuit? If so, it may be going bad. Just a shot in the dark.