My alternator was weak and dying because one of the diodes in it was bad. I never knew this, but both Mercedes and the old German guy I use who used to do electric work in Germany for MB told me NEVER jump someone and crank YOUR car, too. If you're going to jumpstart someone leave YOUR KEYS IN your pocket. "If they don't have triple A that's their own fault..we don't have to pay for roadside assistance-it's free." I wanted to point that out for any newbies because when I had my 1967 sel I never knew it and payed for roadside assistance b/c I thought it was only for newer models under warranty-it's not..all mb drivers . and they've been very nice and come out several times once in the middle of the night to get me started again.