93 defroster

i have a 93 aerostar that the vents on the dash will blow you away
however the defroster seems to have little coming out of it.
a guy a work also has a 93 and the same amount of air comes out
his as mine.
is this normal for such a big windshield,or as i've heard mentioned
could the vent be plugged by a pen etc.
thanks.


























away ,however the defroster vents even on high don't seem to