What was found
(CAN) ACFT DEPARTED TERRACE AND WHEN GEAR WAS SELECTED UP IT DID NOT OPERATE. IT WAS CYCLED ONCE MORE WITH NO EFFECT. THE GEAR INDICATION SHOWED DOWN AND LOCKED SO THE CREW ELECTED TO LAND WHERE MAINTENANCE MAINTENANCE WAS AVAILABLE. LANDED UNEVENTFULLY AND DURING INSPECTION BY MAINTENANCE, NO POWER WAS PRESENT AND THE GEAR MOTOR RELAY. SUBSEQUENT TROUBLESHOOTING REVEALED A DEFECTIVE WITCH IN THE GROUND SERVICE VALVE. IT WAS REPLACED AND THE GEAR SWUNG NUMEROUS TIMES WITHOUT FAILURE. THE AIRCRAFT WAS RETURNED TO SERVICE.