Usually, the backup camera connects to the reversing lamp. But if you install the OEM BMW Android screen and install the backup camera like this way, you will meet problems, such as the screen keep flashing, or just black screen when you back the car. 
                                     (the camera cables on our power harness)
backup camera installation wire diagram

The correct way should be: Connect the "Camera +12V " cable (which from our Android screen) to backup camera. It means, your backup camera gets the power from our Android screen, and this is the only power source for the backup camera.

Remark:

A,  If you install the normal backup camera, connect the power cable: Camera 12V & Camera video input (yellow connector), Don't connect the "Camera Det".

                         (wire digram for the normal backup camera)
B, If you install a 360-degree camera (bird view camera system), then you need to connect "360 Camera DET" & Camera video input (yellow connector). Don't connect the "Camera +12V"

Video demo:



Camera settings

If you install the backup camera and find it not work, you need to go to the settings and make a proper setting for your backup camera.

The part is: Settings / rear camera

Remark: If your camera is the original camera, then choose "original camera";

if it is an aftermarket camera, then choose "aftermarket camera "


rear camera setting interface
                                            (camera setting interface)