Dan,

  The fix I suggested does not permanently seal the vents off.  I simply applied the foam around the edge so it creates a seal when you move the lever to the closed position.  If you have any luck fixing the defrost vents by removing the grill, let me know.

  Clint (former Wisconsinite)

-- Dan Roberts <danielcroberts@AOL.COM> wrote:
  Clint:
Thank you for the suggestion. Another writer suggested accessing the vents
by removing the front grill. I think I will try that approach.

However, I live in Wisconsin and must have access to hot air in the winter
so I can't permanently close off the vents. Fortunately, I store my Vanagon
for most of the cold season.

Good driving,
Dan