1992 Cadillac Brougham poor windshield defroster performanc

Air Conditioning problem
1992 Cadillac Brougham V8 Two Wheel Drive Automatic 52750. Miles

when I use my defroster to keep the inside of my windsheild free of 'fog up', it doesn't perform as it should. The blower works properly on all speeds, but it cannot keep the inside clear. It is able to clear a small area directly above the defroster outlets. The car does have automatic climate control, and seems to work properly; however, in the summer I don't feel that the a/c blows as cold as it should. Any suggestions? Thanks.