These instructions are for a negative earth vehicle. To have this operate as a camera that comes on when reverse is selected the wires need to be attached as in the above photograph. It is important to get the polarity of the camera wires correct or it can ruin the camera. The inside of the plug is positive and the outer negative. The wire colours vary depending on the camera. They do use red as negative on some which we take as positive! I always mark the camera box so be guided by that. Always check it operates before you begin installation. I always check items before I send them out, but I have had items get damaged in the post. The square box holds a fuse and it is not unknown for that to shake loose. The green wire of the monitor is usually attached to the positive supply of the reversing light. It is easier to run a single core wire to the rear of the vehicle and use the same point you attach the camera. A fuse on this connection is important. If you want to control the camera and monitor with a switch to have it always on then attach the green wire and the +ve wire for the camera to a switched 12v positive supply.