What was found
IAH - FLT 2078 - AFTER TAKEOFF AND GEAR RETRACTION, EN ROUTE TO DFW, LEFT MAIN GEAR INDICATION WAS RED WITH ASSOCIATED GEAR DOOR WARNING LIGHT ILLUMINATED. LANDING GEAR HANDLE RETURNED TO OFF POSITION LIGHTS REMAINED ON. ADDITIONALLY LEFT GEAR GREEN LIGHT ILLUMINATED. AT GEAR DOWN, ALL INDICATION PLUS VISUAL INSPECTION SHOWED 3 DOWN AND GREEN LIGHTS, NO RED LIGHTS. RETURNED AND LANDED IAH WITHOUT INCIDENT. SECURED A 12 INCH SEAL HANGING DOWN FROM LEFT GEAR WING DOOR END PLATE. DID MX FERRY TO DFW FOR PERMANENT REPAIRS. EN ROUTE DFW GRIPE REPEATED. LANDED DFW WITHOUT INCIDENT. REPLACED LEFT MLG DOOR ACTUATOR. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)