My Mercedes E320 Won#039;t Start: Troubleshoot

1. Insert your key into the E320's ignition and turn it. Listen for a 'clicking' noise. If you hear the clicking noise, you will need to have the car towed to a garage to have the alternator replaced.
2. Look at the fuel gauge while the key is in the ignition. Add gas to the car if needed and then try to start the E320.
3. Open the E320's trunk and locate the battery. Make sure that the battery terminals are connected to the battery properly. You can tell this by the '+' and '-' signs on the terminals and the connecting wires.
4. Connect jumper wires to the '+' and '-' terminals on your battery and then connect the other end of the jumper wires to a different car battery. Start the other car with the wires connected and then try to start your car.
5. Leave the E320 running for about 15 minutes to allow the battery to charge. Turn the E320 off and wait for a couple of minutes. Start the E320 again. If the car will not start, you need to replace the battery.