factory fit reverse cam power

if you were to use one of the "factory fit" reverse camera looms from carsystems wiring loom where does it take its power feed from is there a  pure 12v output on the back of the radio or would it come direct from the BCM just curious as don't really want to break into the rear wiper feed or reverse lights unless I really need too 

Edited 12 February, 20197 yr by Bigtow