A/C Blowing air out at dash when in Floor Mode

[Moneyhan]

Hi,

I have a 2004 National Dolphin 6335. It has the Workhorse Chassis with the 8.1L Vortec engine. When I turn my AC control dial from dash mode to floor mode I still get air full blast at dash and very little on the floor. I found 2 vacuum valves that adjust the doors and both work when I switch modes. Could there be a third one? I noticed this when trying to do some troubleshooting to see if the mixing door was closing all the way to only allow cold air when in A/C mode. Still have not figured out where that control is. Any ideas or suggestions would be greatly appreciated.

Thanks in advance