Hi I am a newbie and just purchased a 1991 300SL and I can't get the Hard Top to unlatch.I spoke with a Benz guy on the phone and he mentioned that if the car was sitting for a long time and the battery was dead that the alternator needs to be at a certain voltage to unlatch the top.It sucks down but won't release.has any one had this problem or maybe can advise? I put a volt meter on the battery and when the car is running it is only charging at like 13.5 volts.