Vents are stuck. Help!
 

So the other day I put on my defrosters and after defrosting the windshield I went back to vent. Except that it stayed in defrost. I really don't know what to do in this case. I drive an 89 Laredo. Does the vent switch physically change the vents or does it engage a motor to switch the vents? Any help or info would be great. Thanks

ran off vacuum, in my 94 the vacuum ball is in the passenger side bumper, idk about your renix though