First Problem (maybe): Had a Motion Sensor in series between Switch and Turret. Re-read schematic and saw that Motion Sensor was part of Turret construction. Once I removed Motion Sensor, I could manipulate control of camera vision. Still couldn't load any ammo into turret.
Second Problem (also maybe): Maybe it was a wonky turret. Built new one, mounted in same place with same wiring (but no extra Motion Sensor) and it took the ammo OK. Now to see if it will handle vultures on Day 56.... Junk Turret taking down some of them, but not all.
Thanks again for prompt response, meganoth. "Buggy turret" comment spurred me to try replacement fix.