What was found
AFTER A NORMAL DEPARTURE WHILE CLIMBING THRU ABOUT 15000' THE LEFT GEAR DOOR LIGHT ILLUMNINATED FOR ABOUT 20 SECONDS. REDUCED POWER AND BEGAN SLOWING TO 200 KIAS, AT ABOUT 240 KIAS GEAR LIGHT EXTINGUISHED, APPROXIMATELY 30 SECONDS. LATER AT 250 KIAS THE LIGHT ILLUMINATED AGAIN. RETURNED TO DEPARTURE. MAINTENANCE REPLACED THE LEFT MAIN GEAR DOOR UPLOCK SWITCH AND ADJUSTED, PERFORMED MULTIPLE SWINGS WITH SATISFACTORY RESULTS AND A SUCCESSFUL OPERATIONAL CHECK FLIGHT.