As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EVAC HORN CONTINUOUSLY SOUNDS. CONFIRMED THAT CIDS DIRECTOR 2 WAS CAUSING THE FAULT. DEACTIVATED BY REMOVING AND TERMINATING THE GROUND WIRE TO THE HORN FOR FERRY FLIGHT TO IAD FOR REPAIRS. ON TERMINATION OF FERRY FLIGHT RECONNECTED THE GROUND WIRE FOR THE HORN. REPLACED AND TESTED CIDS NR 2 PER MM. TESTED EVAC SYS PER MM, TESTS AND INDICATIONS ALL NORMAL.