OK, no "fails" in Single Missions. I still have to test the career mode, and see what not only the radar does, but also the conning tower...
Started with the Gar, July 1942 Midway, since that's what torpedobait had:
The Tambor, since it is the same boat:
The Tambor again, one year later:
The Tambor in July 1944:
In all of the above, when first coming into the game, the parabolic radar dish was rotating, and the NavMap showed radar contacts. If I went back outside, the rotation had stopped. Going to the station, or using the keys, I could turn it on and off just fine, or click on the menu's "Continuous sweep" button, or the switch on the console itself, and I would then have rotation again. Change stations, and it would apparently stop... We will have to consult with our resident animation expert(s) about that. More findings later.