If that is the 12v I'm thinking of then it goes between the VFD and the control board. The vfd has a 12v pos & neg and they go to the board and this is the power that is fed back to the vfd for control. It is a straignt hookup. If you have the paper work on that vfd it should be noted. if not then give Tommy a call, he'll have it back at ya in 20 seconds or less.