OK, I don't think the realism settings have anything to do with it, but I could be wrong. As long as I've been playing, when I go to the radar station, it automatically shuts off and I have to turn it back on again.
As far as the radar shutting off and starting up intermittently, the only time that may happen to me (fully surfaced# is during extremely rough seas where the waves wash completely over the boat. It will happen if you're running decks awash in rough seas or are partially submerged. The stock version is very buggy but the mods fix a lot of those problems. Before you start a new career, do you go into your #:My Documents/SHIV/Saved Games) folder and delete all the old data? I have sometimes had issues where old and new files become corrupt and/or interfere with gameplay. At least, I haven't had any real problems since I started deleting my old saved games data before starting a new career.
It's probably just me, but I'm still not sure what you mean by "contact updates". They're not radar, not sonar, but contact updates?
