Is there a wire attached to the pin? If so, what color is it?
Give us a list of the numbers corresponding to the empty holes of the D-Sub connector.
According to Van's schematic, the following holes
in the Options harness D-Sub connector are empty:
5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 36
If there is an additional hole empty in your connector,
then that is where the pin goes that fell out.