Wiring problem

What is the sensor for? Is it a factory part or something like an aftermarket camera or warning system? If it's an aftermarket item could you post the make and model of the unit. That would let us look up the wiring. I think you are adding a back-up camera that needs a ground and a signal from the back-up lights but without knowing which wire was which on the part you have I wouldn't want to have it wrong.