92 Sonoma, AC only blows floor and Defrost

[Dreamstar]

Ok, I have looked all over the forums, and can't find anything on this. From what I have read, I figure it's a vac leak. Problem is, I can't find any info on where the bulb is, or any of the vac lines are, or where to look. I replaced the blower motor a few months ago, cause it wouldn't blow at all. But it won't blow through the vents. And on an Alabama summer day, you want cold air in your face. Anyway, any help would be appreciated.
Oh, it's a 2.8 V6 TBI