As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT MAIN LANDING GEAR DOWN INDICATOR DID NOT ILLUMINATE ON INITIAL GEAR EXTENSION. CYCLED LANDING GEAR AND LIGHT ILLUMINATED. FOUND CORROSION IN THE LEFT GEAR DOWNLOCK SWITCH AND MOISTURE IN THE CANNON PLUG. CLEANED CORROSION FROM SWITCH AND REMOVED MOISTURE FROM THE CANNON PLUG. OPS CHECKED GOOD DURING GEAR SWING IAW DC-9 SUPPLEMENTAL M.M. 32-60-00.