Originally Posted by BillBoost37
On that fan speed. it should be whatever is selected. Sounds like the vents may be starting to work at a point, however I would believe they are not fully engaged. Meaning the airflow is being split three ways and seeming like you are getting less flow
I don 't know what vacuum guage to get
If you can hear any "hissing" down by your passenger side hush panel (or even better, from the HVAC box/connector with the hush panel removed) then the line connectors are pinched/collapsed and you need to do the "connector replacement with vac lines" part. This was my problem and I never did check vacuum at source/tank/or along the path to the interior. If you don't hear hissing, then you need to pick up a vac guage (ask them at the auto parts store what to get) and begin tracing at the source, off of the engine, to the resavoir tank, back to the Y connector, then into the interior.
Good luck and let us know how you are doing!