Location reverse camera/sensor fuse 2011 ex ambo T5

Hi everyone, this is my first post on this site, and I was hoping someone could help me.
Six weeks ago I purchased my second T5 ex ambo, this one a December 2011 model. Unfortunately both the reversing camera and sensor stopped working yesterday, so I'm assuming a blown fuse. Had my mechanic do a quick check of all of the known fuses and they were all operational. Was advised that given that the camera and sensors are after market fitted by the ambos there is no way of knowing how they are wired or fused without timely exploration by the mechanic. I assume the ambos wired these the same way and maybe someone out there has had the same problem and will be able to assist me with the location of the fuse or point me in the right direction.
cheers
pete