Another HVAC problem

So everything was working great earlier this spring when I checked it all out.
For some reason now when I switch to Max A/C it switches to defrost only. Or sometimes I will get a little air through the vents but mostly through the defrost.
The odd thing is when it is just on A/C it works fine. All other settings seem to be fine as well.

Any thoughts? Could this just a vacuum leak? I did replace lines up near the accumulator last winter. The new line is squished too if that brings up any light bulbs.
Almost forgot; '95 4x4 Blazer.

Thanks in advance for the tips.
Joules

Check the vacuum line, (and the actuator) for the recirculate door. Just above passenger feet and has a black plastic grille over it. Might have to remove the kick panel to get at the actuator.

After much searching on other Blazer forums I have confirmed what my problem is.
The vacuum switch in the transfer case is bad causing tranny fluid to be sucked up into the selector.
Apparently since I just recently tested out 4Lo that's when the problem started.