The same thing happened to me.  My problem got progressively worse.  It
ended up being the cable inside the door that got loose.  The lock nut
that keeps the cable tight had worked itself loose so the cable got out of
adjustment and too long.  I had to take the door pannel off and then
adjust the cable to make it a little shorter and then snug up the lock
nut.  You can see how this works in the Bentley 58.7.

Pascal
'84 Westy