What was found
AFTER LOWERING LANDING GEAR, LEFT MAIN GEAR DOOR LIGHT ILLUMINATED ON SECOND OFFICER'S PANEL. RECYCLED GEAR AND LIGHT EXTINGUISHED. CHECKED DOOR SWITCH FOR SECURITY, NORMAL. CYCLED DOOR, INDICATION NORMAL. FOR PRECAUTION DEFERRED LEFT GEAR DOOR WARNING SYSTEM. CLEANED CANNON PLUG ON LEFT MAIN DOOR SWITCH, SYSTEM OPERATES NORMAL, AND PER FLIGHT CREW DOOR LIGHT OPERATED NORMAL ON LEG OF FLIGHT.