(1990 560sel) Starting Issue (Please Read)
While I'm jumping my car off it starts while still connected to jumper cables and running car its connected to. I disconnect the jumper cables while my 1990 560sel is still running. It stays running and I can drive around. But once I shut it off it goes dead. It slowly became harder and hared to start over time. Everything works fine that I can tell. What do you guys think? (Going on a trip and need it working proper.)