Hello,
I got a used Walkera G-3D 3 axis brushless gimbal and it came with all cables except the power convertor cable. It has a power connector like this:


So there is no colour coding that can specify which is +12v and which is GND. Can anyone tell me which is what?
Also I noticed that one pin is shorter, does it mean it is GND? Like one in LEDs??
Thanks

Check with a multimeter. If the Gimbal has wires for controlling roll pitch or yaw. Just put the multimeter on continuity and check the continuity between one of the Pin of the connector (the pic you have posted) and the cable of the control(Roll, Pitch or Yaw use any one of them). If its a ground wire it will beep(Common Ground), no beeps for 12V wire! try all possible combination. Hope it helps!