As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED MAIN CARGO DOOR ANNUNCIATOR ILLUMINATED WHILE BEING VECTORED AND DURING DESCENT. PERFORMED EMERGENCY PROCEDURE AND DECLARED AN EMERGENCY. APPROACH AND LANDING WERE CONDUCTED WITHOUT FURTHER INCIDENT. MAINTENANCE VERIFIED A BAD AFT LATCH LOCK PIN SWITCH. R & R SWITCH AND RIGGED IAW MM 52-35-08. SYSTEM THEN OPS CHECKED GOOD IAW MM 52-35-08. ACFT WAS RETURNED TO SERVICE.