heater only blows out defrost

["Southerlin, Russ S" <STHRRSAB@edex.litc.lockheed.com>]

I have just purchased a 87 5KTQ and the auto climate control seems to
act weird. It seems to only blow  primarily out the defrost no matter
what the setting are on. The Bi-Level setting will blow out the vents
but little or none get down the the footwells. The manual says
Bi-Level should blow out the footwells also. If anyone on the Q-list
has knows a fix, or is this the way it is supposed to be I would
appreciate it. 

My feet are COLD!!!!