What was found
DURING CLIMBOUT, THE GEAR UNSAFE LIGHT REMAINED ON AFTER GEAR RETRACTION. PERFORMED GEAR UPLATCH CHECK AND THE LIGHT EXTINGUISHED, RECYCLED GEAR AND THE LIGHT AGAIN REMAINED ON. RETURNED TO MSP AND LANDED WITHOUT INCIDENT. REPLACED THE LEFT MAIN LANDING GEAR UPLIMIT SWITCH AND CANNON PLUG, GEAR OPERATIONAL CHECK GOOD.