91 wagon blower problem?

I've got a 91 wagon and the blower doesn't blow hard anymore.. I tried a new blower motor but it's the same.. I can here it go from low to high in steps like it should but doesn't come out of the vents in the floor or the air vents very hard... This summer it would blow your hat off your head but now it just acts like on low when it set on high..HELP!

Thanks Rob