I Have a 1990es 250 I to am having the same problem. I have changed the battery Terminals, unplugged the battery for a period of 24 hours. And still my car won't start. Tomorrow I'm having the stater tested I'll let you know if it helps any. But I'm also stumped on it. Sorry I can help any but I do know from my own trial and error changing the battery, the terminals, or charging is helping any.