What was found
EN ROUTE FROM TOL TO JFK, THE LANDING GEAR DOOR WARNING LIGHT ILLUMINATED AFTER GEAR RETRACTION. THE FLIGHT CREW CYCLED THE GEAR WITH THE WARNING INDICATION REMAINING THE SAME. THE FLIGHT CONTINUED TO JFK FOLLOWING COMPANY PROCEDURES. MAINTENANCE INSPECTED THE LANDING GEAR AND DOORS INDICATION SYSTEM WHICH REVEALED THE LEFT MAIN GEAR DOOR SWITCH CONTAMINATED WITH MOISTURE. MAINTENANCE CLEANED THE SWITCH CANNON PLUG AND PERFORMED A SUCCESSFUL OPERATIONAL CHECK. THE AIRCRAFT WAS RETURNED TO SERVICE.