Back in 2001, I experienced "Vanagon Syndrome" in my '84 7 passenger
several times.  I removed the cover to the AFM track and cleaned the
track with a pencil eraser and a lint free cloth.  I haven't had the
problem since.

BTW, I was prepared to remove the board and "Oval" the holes that the
Phillips head screws go through so I could reposition it giving a new
track to run on.  Examination showed that the original track had not
worn through so I only cleaned it.

Mike
Houlton, Maine