If you have to jump start your Mercedes, it may indicate you have other problems. It could be a sign the battery is dead or perhaps the alternator is about to go out. In most cases, the headlights were left on. Make sure everything is off before jump starting the car.
Find the battery. It's usually under the hood, but in some Mercedes it's in the trunk or under the seat.
Place the red clip on the positive terminal of the battery. The positive has a plus symbol.
Place the black clip on the negative terminal of the battery. The negative has a minus symbol.
Place the other end of the cables on the corresponding terminals of the battery of the running vehicle.
Attempt to start the Mercedes. The other vehicle should be running. If the Mercedes does not start right away, let the other vehicle run for several minutes with the jumper cables attached. This may charge the battery enough to start the Mercedes.
Remove the jumper cables if the Mercedes starts. Allow the car to run for 10 to 15 minutes to charge the battery. Turn off the engine and let the car sit for another 15 minutes.
Try to start the car. If it doesn't start, the battery is dead and needs to be replaced.
