Servo wires all Black, plug can go in either way
 

I have the Ryan Caveleri Savox servo and im mot sure which way the plug goes in the reciever. The reciever came with my Futaba 4pv. The plug doesnt have the ear that only lets it in the recoever one way.

Signal and ground are on the outside pins and power is on the center pin.
If the servo doesn't work simply remove the plug, turn it 180 degrees and plug it back in.