I was having trouble with my battery going dead on my 560SEL. Meter showed low/no charging. Turned out to be bad connection. Look at the terminal block on shock tower by battery. Three terminals under a plastic cap. Two heavy duty wire sets and one small dia. one. Remove the nuts and then the wires. Take a wire brush to everything. Reassemble with some sort of anti-oxidant compound. I couldn't believe that was the problem until I started checking with DVM. 15 years of black dirt on the connectors was enough to stop the current. Was really wierd to see full voltage coming out of alt. , but not showing up at battery.