OOOOKAAAAAY…. your degree should come in handy ;-) and thanks for letting me know. I can converse on a different level, but I still need to be treated as a 7-year-old please.
Here’s another link of fundamental information, although I imagine you have found it previously.
http://ae64.com/Rear-camera-16p-operation.htm
and
http://forums.nasioc.com/forums/show...28&postcount=9
I would prefer using the Rear camera input for sure as I hope operation can be done by just pressing a button added to the dash and without having to change screen modes etc.
The 3 positions idea is correct. I envisage 2 of the positions with a dash button where pushing it once ensures the rear cam is off and turns on the front cam and pushing it again turns it off. Position 3 would be simply selecting reverse gear to turn the rear cam on or off. If the front cam had been left on I suppose you might notice double video and know to press the button off to just show the rear camera, thus simplifying the wiring. I sense you know that is not feasible for some reason that I have yet to grasp.
Introducing a second switch would just be less than ideal but fine if necessary.
I have yet to splice into the reverse wire but doing so would not bother me and by the time I got a harness I expect I would be $40 poorer. If I had to access pin 13 on the 28pin CN6 socket and the shield pin for video then I would not hesitate getting a harness as there is no wire in the plug now.
WOOPS..... I just noticed your hand drawn info which you must have been doing while I was composing the above. Please take a break while I digest it and I will be back, but probably not until tomorrow. THANKS HEAPS. Are you an insomniac? It is getting towards noon here.