yes, each one will have two wires.

mine was wired up as follows:

hit the reverse switch, the power from the reverse light trips a relay which sends a ground to the input trigger for the camera, and completes the ground to the camera which energizes the circuit and displays a picture.

a switch provides a ground signal just distal to the relay


reverse light positive -> relay 85

ground (earth) to relay 30 and 86

connect the earth leads to 87 from the earth (ground lead) from the camera and the camera trigger on the BMW cable


the you can add a switch between ground and the connections of pin 87; whenever you ground the switch, the camera turns on and the video module switches to this as the input.