This might sound kinda 'not-helpful', but ya just gotta start looking. It could be a wire or tie-wrap inside your pedistal, to a bad pulleys/cable, to some stowed bag or life jacket, or line that has fallen into the quadrant, to maybe barnicles or piece of wood that floated into the gap between the rudder and the hull. If you don't see anything obvious (try moving it while inspecting the various parts), then you start eliminating things, like loosen the cable and see what moves and what doesn't, and then keep digging until you find the problem. The solution is usually straight forward; fix what is broken then see what needs or can be done to prevent it happening again. Good luck and if you take pictures and do a writeup on what you find, it might help the next 33 owner,
Kb