93 Sundance Fan Blower Slide Switch Stuck

The fan blower slide switch is stuck in one position on my 93 Sundance. It just won't move. Fortunately it's on almost high so I get air but I just can't slide the switch either way. Looks to me like a mechanical problem. Maybe something is stuck behind it? Do I need to rip the dash off to look at it? Any suggestions would be appreciated. Thanks!