, a Merlin II with 4 people on board, was on approach to Runway 36 at Winnipeg after a flight from Thompson when the crew reported an unsafe gear indication. The crew overshot the runway and held east of the airport to work on the problem. The crew advised that they obtained a safe gear indication after using the manual system. After a fly-by of the Tower to visually inspect the landing gear, the flight landed safely with ERS on standby. No other a/c were inconvenienced. OPI - Maintenance and Manufacturing UPDATE M. & M. reported that on final approach, the pilot selected gear down and the gear would not lower. They then elected to circle to determine the cause. After a bit of looking they found that the landing gear circuit breaker had popped, so they reset the breaker and the gear came down. Upon examination by maintenance, it was found that the clutch, which is part of the motor assembly, was slipping and allowed the motor to run continuously, therefore popping the breaker. The motor assembly, complete with clutch, was replaced. The required maintenance actions were completed and the aircraft returned to service. An SDR will be submitted after disassembly by the overhaul agency to determine the cause.