As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
OAK - UPON APPROACH INTO OAK, LEFT GEAR UNSAFE LIGHT DID NOT ILLUMINATE WHEN THROTTLES WERE RETARDED. UPON GEAR EXTENSION, LEFT GEAR GREEN LIGHT DID NOT ILLUMINATE. PERFORMED LOW PASS FOR MAINTENANCE AND CONFIRMED GEAR WAS DOWN. NO HORN NOTED AT FL 40 AND HORN WAS SILENCED BY GEAR EXTENSION. FOUND BAD SWITCH AND CANNON PLUG. (M)