See
http://www.uboataces.com/radar-warning.shtml for a pretty good historical overview of Uboat radar warning tech.
In brief, unless you have the FuMB-35 Athos (which was deployed on a few XXI's at the very end of the war) or the FuMB-28 Naxos ZM (which was still in development at the surrender and didn't see service) -- both of which had a CRT display which could show bearing to the transmitting radar -- all you should get is the crewman's notice about "radar detected". In other words, virtually all RWR sets used by the ubootwaffe were like the radar detector in a car....you get an indicator light or an audible tone and that's it.
Playing with NYGM 2.2, I actually *DO* get bearing lines from the radar warning, even with METOX. I wish I knew how to turn off the bearing lines, because it isn't realistic for VII or IX ops, and it makes it trivially easy even at 100% to end-around radar equipped escorts and dive for a submerged attack on a convoy.