I've read that if the 2 center vents do not blow AC on the 560SL that it indicates a heat box issue. Mine center 2 do not blow.
What exactly is the issue that needs to be fixed?
Does the heater not work when there's this issue? Step duaghter has the car so I can't go out and try it at the moment.

Any writeups on how to fix it? I know you have to take most of the under dash apart, nothing I can't handle if there's some sort of write up on it.

Thanks

 

I welcome you to http://users.adelphia.net/~rmsmithco and follow the links. You can get an idea from my experiences (and others reported) there. Also, follow the links to benzworld.org and mercedesshop.com for more info.

good luck.