I am not that familiar with the SLK, but my SL requires a synchronization procedure before the top will go down. Check your owners manual and then give the dealer a call. The battery being disconnected will reset it, but then you have to re-sync it so the computer knows where everything is, or a place to start. Good luck!
Brian

__________________
Brian W. Heitman

www.MBCA.org/northtexas

Join MBCA!!!