What was found
RDM - FLIGHT 2128 - THE LANDING GEAR INOP CAUTION MESSAGE APPEARED IN FLIGHT AND THE LEFT MAIN GEAR AMBER LIGHT ILLUMINATED. THE CREW VISUALLY CHECKED AND VERIFIED THAT THE DOORS WERE OPEN. THE CREW COMPLIED WITH THE LANDING GEAR INOP CAUTION LIGHT CHECKLIST AND USED THE MANUAL GEAR EXTENSION. MAINTENANCE INSPECTED THE AIRCRAFT AND FOUND THE CONNECTOR IN THE LEFT WING ROOT NOT FULLY SEATED. THE CONNECTOR WAS THEN CLEANED AND RECONNECTED. OPERATIONAL CHECKS WERE GOOD AND THE AIRCRAFT WAS RETURNED TO SERVICE.