Blower Vent fix....cheap!!
I know a lot of us had had various problems with the interior vent switch 'not working'. Ususal suspects are the switch, or vacuum lines. I have a 2002 Sport.
About 3 months ago the selector switch didn't work. The air, (ac/vent/or heater) pretty much just came out of the top dash defroster vents, and the bottom center floorboard vents. Couldn't get the air to come out of the front dash vents for anything. Everything works, blower motor, ac, heat....just no center vents. (try running the ac on a hot day with only your feet getting cold air.
Anyway.....mine was a vacuum line. I got the suggestion on this site to trace the lines ALL the way. I did. The culprit was on the engine side of the firewall, just infront of the passenger side. The line goes from a skinny hard plastic tube, into a wider standard rubber tube and snakes its way into a box behind the right front wheelwell. The tube had dry cracked and slipped off. Nothing more.
I cut off a half inch of the end, stuck it back on.......viola! Everything works.
So if your experiencing this issue, you might want to check the engine side of the firewall first before pulling the glovebox and trying to trace the individual colored vacuum lines that feed into the back of the switch.