Camera Wiring: Schematic or Diagram for the harness pins? 2007 RX 350

[ImpendingDoon]

I've searched the forums, but could not find what I was looking for. Apologies if this has been asked (and answered before).

I am installing one of those Tesla Style head units in my '07 RX 350 (with ML audio and nav). Got almost everything working... except for the OE Camera. I know it's a 6v device, so I bought a step-down converter. I'm good from the radio side. I have a harness that came with the radio, but I think the pins are incorrect.

From the radio I have a switched 12v that comes on when I put the car into reverse. I've got the step-down converter hooked up, but don't know which pin in the harness takes power to the rear camera. I have a signal wire carrying 2.5v (from the radio) that goes into a second harness which should go back to the camera. I the typical RCA connector, in that harness, too.

This can't be that hard. I need power, ground and a signal.

Can anyone help?