As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) LOW ROTOR HORN NOT WORKING BUT LIGHT ON 4ALPHA PANEL WOULD COME ON. SYSTEM TROUBLESHOT AND FOUND SWITCH TO BE INTERMITENT. A/C GROUNDED TILL NEW SWITCH HAD BEEN REPLACED. THE POTENTIAL FOR GIVING A FALSE READ TO THE PILOT DURING FLIGHT MAY HAVE OCCURED. AIRCRAFT WAS GROUNDED. SWITCH HAS BEEN REPACED AND A/C RETURN TO SERVICE. (TC NR 20070316001)