A/C Blower?

My A/C blows super cold so theres no problem there,especialy when I live in Florida.Usually I have the blower on the upper vent or the head position.But today I was wearing my loafers without sock and my feet were a little sweaty [yuk] so I switched to the lower vents or the feet position but my toes got a little cold so I switched to the middle position or the head and feet but air only blew out the upper vents.They work perfectly by them selves but when you combine them air comes out the top and not the bottom.Any ideas?Has anyone had or has this problem?

Thanks
P.S. Sorry about the feet I probably could have left that out.

Check vaccum hoses (the diagram on the hood), mine was that.

Thanks, hope this helps