Slk 230 1998 Battery Died Had It Replace Now Phone Wont Work Why???

PLEASE HELP ME!
I HAVE A MERCEDES SLK 230 1998 , LAST MONTH THE BATTERY DIED , WHEN I REPLACED IT THE CARS REVS WHERE GOING UP AND DOWN LIKE SOMETHING WAS WRONG... I WROTE TO YOU GUYS AND I WAS TOLD TO LEAVE THE KEY ON THE SECOND POSITION FOR A MINUTE AND THEN TURN THE STEARING ALL THE WAY TO THE RIGHT AND LEFT SEVERAL TIMES... THAT WORKED FINE!
BUT NOW MY PHONE WONT START . I CHEKED THE FUSE BUT IT LOOKS OK!
WHAT CAN BE WRONG ? PLEASE HELP
THANK YOU!