Defrost Bleed
WARNING: This page is about a different car, the 1994 Honda Prelude. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Position of defrost door can be adjusted so no air or as much as 20 percent of air is distributed to the defroster vents when airflow control is in heat mode. Use this procedure to adjust the amount of bleed air.
Loosen adjusting screw. See Fig 1 . Adjust linkage until desired amount of airflow is achieved. Tighten adjusting screw.