Amana air conditioning unit, several years old. Set thermostat to Cool, current hone temp is 77, set temp is 75. I can hear the furnace fan running but house is not cooling. Checked circuit breaker and AC breaker was flipped so I turned it back to ON. House still not cooling. Went outside to check AC unit and it's not running at all (neither the fan or compressor). Opened up what looks like a small panel outside and there's an on/off setting with a steel bar over it. Flipped this bar up so it is overtop of the ON setting but unit still not running. Any suggestions before I call service? Thanks