the center vents aren't working on my daughters 89 260E. Anyone had this issue? How can I fix? DIY links? Photo aids?

Thanks!!

__________________
1973 280 - Sold
1980 300SD - Sold
1982 240D - Stolen
1988 300E - Sold
1989 260E - Sold
1989 560SEL
1994 E420 - Sold
1997 E420
2005 CL500