Working again! Spent another hour retracing connections and I think the issue may have been in the grounding relay where the camera gets power-but that does not explain why the tuner module wouldn't accept a different source, would it? I did not find anything conclusive, just a lot of time spent doing it all over again. All this because a non OEM shop 'eliminated' by disconnecting the 'aftermarket' items.

I guess bottom line is, sometimes these things are flaky. Good luck if you have the problem