As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT CREW RETURNED TO THE FIELD AFTER RECEIVING A CARGO DOOR LIGHT INDICATION. THE AIRCRAFT LANDED WITHOUT INCIDENT. THE DOOR WAS INSPECTED, FOUND TO BE CLOSED, THE SYSTEM DEFERRED AND AIRCRAFT RETURNED TO SERVICE. MAINTENANCE INSPECTED THE SYSTEM FOUND A BROKEN WIRE AT THE SWITCH. THE SWITCH WAS REPLACED AND SYSTEM INDICATION OPERATED NORMALLY. DEFERRAL WAS CLEARED.