As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON GEAR EXTENSION LEFT MAIN GEAR DOWNLOCK LIGHT DID NOT ILLUMINATE. RECYCLED LANDING GEAR AND DOWNLOCK LIGHT DID NOT ILLUMINATE. DOWNLOCK LIGHT CAME ON DURING LANDING. CLEANED LEFT MAIN GEAR DOWNLOCK SWITCH CANNON PLUG AND REPLACED DOWNLOCK SWITCH. GEAR RETRACTION AND GEAR INDICATION CHECK WAS GOOD IAW DC-8 MM.