What was found
DURING A NIGHT APPROACH, AFTER EXTENDING LANDING GEAR, LT MAIN GEAR INDICATION LIGHT DID NOT ILLUMINATE. ABNORMAL CHECKLIST WAS COMPLETED FOR THE GEAR ABNORMALITY. GEAR INDICATIONS LIGHTS TESTED NORMALLY. HYD AND ELECTRICAL SYSTEMS WERE NORMAL. ON THE THIRD LANDING GEAR RECYCLE, LT GEAR INDICATION FLICKERED AND BECAME STEADY BUT EXTREMELY DIM. LANDING AND TAXI WAS WITHOUT INCIDENT. TROUBLESHOOTING IDENTIFIED THE LEFT MLG DOWN/LOCKED SWITCH AS DEFECTIVE. A NEW LT MLG DOWNLOCK SWITCH WAS INSTALLED. OPS CHECKS WERE SATISFACTORY AND THE ACFT WAS RETURNED TO SERVICE.