Aftermarket Radio to Factory Camera
 

Hello everyone, I am new to this forum! hoping yall can help.
I have a 2015 CX-5 Sport, with the touchscreen and reverse camera. The factory head unit was terrible so I decided to replace it.
I got a JVC m740bt, PAC wiring harness, and MAZCAM-6v reverse camera adapter.
Everything is working except the reverse camera. Crutchfield is saying I have to splice into the factory harness (GREY/WHITE) from the rear BCM to make this work, but a video I watched said I have to just run the blue/white from the PAC harness (AMP TURN ON) to the reverse cam harness.
Has anyone done a Aftermarket Headunit- to Factory reverse camera?