MB AMG

I have a 1992 600SEL that has just been serviced at the local MB dealer. For some reason I left the damn reading light on and the battery drained. I used a recharger and when i checked it up the next day by starting it up, the active suspension light on the dash lit up. It won't go off and I don't know what to do. It's happened before when the battery drained prevously so it can't be the suspensions problem. The manual says take it to the dealer and that's it. Anyone got a clue on what the problem is? Do you think I should put AMG monoblocks 9.5*18 / 275/35ZR18's in the rear and 245/40ZR18's in the front? Does anyone know if the'll actually fit and if I should even put new wheels on the car? If so let me know.