Almost finished with a double din sony xav-ax100 install with back up camera and I just have one wire I am struggling with. I wanted to run the camera and radio reverse signal up in the dash. This way i can run a toggle with one pin to the reverse signal and the other pole to a constant hot. I can toggle over if I ever want to look behind the truck at the load I am pulling for example. The problem has been the scarcity of a reverse wire under the dash. If I understand correctly, the column switch for the reverse light moved at some point from the column to the shifter location on the side of the automatic transmissions. Is this correct? Is there any other location in the cab to pull a reverse signal?