Battery Drain Problem
Need help! Battery 2001 C320 drains to zero if not driven every day. Thought bad battery, installed new battery, but still have same problem. Car starts runs and drives ok if driven everyday. Can't find anything staying on in car (lights ect). Disconnected battery ground cable and hooked Volt/Ohm meter in line and measure 12.2 volts drain with everything off key out and doors closed. Any ideas? Car recently purchased, could have been an ongoing problem.