What you will need
- Open the hood of your car. Unlock your car and go to the driver's seat and locate the hood release below the dashboard.
- Go in front of your vehicle, unlock the hood latch and pull the hood up. Use the support rod to hold up the hood.
- Find the positive and negative terminal of your battery. It is located on the driver's side of the engine compartment. To open the positive terminal of the battery simply slide up the red cover.
The red arrow is for the positive terminal and the black arrow is for the negative terminal.
Connect the Multimeter. Before you connect, set your multimeter first to DC voltage. When you are done, connect the positive probe to the positive terminal and the negative probe to the negative terminal.
- Check the voltage of the battery. If your battery is lower than 12V with the engine running, the alternator is not charging.
On most Mercedes-Benz vehicles you can also check vehicle voltage via the instrument cluster. We have a number of tutorials on how to check battery voltage via the instrument cluster. The procedure varies between models.