Trying to start a Mercedes and nothing happens is extremely frustrating. There are a few things that may cause your Mercedes Benz not to start.
So I’ve narrowed down the list based on my mechanical experience and my years of working on Mercedes cars. Let’s get to it.
5 Common Reasons Why Nothing Happens when you turn the Key on your Mercedes
1. Bad Battery
The most common reason why your car won’t start is a bad battery.
You can check your battery voltage by grabbing a multimeter and checking for voltage at the battery.
If the battery reads less than 12.2 volts on the multimeter then chances are the battery is too low or damaged.
Another way to test if a bad battery is causing your Mercedes not to start is you can test by jumping another car into the Mercedes and trying to start it.
If it starts, then your battery is bad and needs replacement.
Your Mercedes needs a certain battery voltage to operate. If you have a bad battery, then your car won’t turn over.
2. Faulty Starter Motor
The starter motor is what you use to start your Mercedes.
If the starter motor is bad or faulty, then it won’t turn over and start your car.
This can be caused by many different things such as a short in the wiring system, corrosion inside of the starter motor from water damage, dirt or grime build-up on brushes within the starter motor that allows for current flow through them causing them to wear out quickly.
3. Bad Ignition Switch
Another common reason your Mercedes won’t turn over is because of a bad ignition switch.
The ignition switch going bad is a known problem with Mercedes-Benz vehicles.
The ignition switch is what allows you to turn the key in the ignition and start your car.
The ignition switch is connected to the battery and starter motor through two wires that allow current flow from the battery to power up your car’s electrical system
Your Mercedes will not turn over if there is no power getting to the starter motor, and that can be caused by a damaged ignition switch.
4. Faulty/Low Key Fob
A bad key fob can also cause your Mercedes not to turn over.
If you have an older Mercedes, then it may be time to get a new key fob or reprogram the old one.
The key fob is used to unlock and lock your car as well as start it.
If the battery in the key fob dies or has some kind of malfunction, then it will not work properly with your car’s ignition system and will not allow current flow from the battery to power up and turn the engine over.
5. Failed Electronic Steering Lock
The final common problem that can cause a Mercedes not to turn over is a failed electronic steering lock.
This is also a common failure that I have seen in many Mercedes Benz models.
The electronic steering lock is responsible for locking and unlocking the steering wheel.
If this system fails, it can cause your Mercedes to be nonresponsive when turning the key.
In other words, your Mercedes won’t start because the steering wheel won’t unlock.
What to Do if Nothing Happens When you Turn the Key on Your Mercedes
Check the Battery
The first thing I personally recommend is to check the battery. A bad battery or one that is not properly charging can cause your Mercedes not to turn over, or even start.
While this is a common problem, it’s also easy to fix by replacing the battery with a new one.
If the condition of your battery is fine but the voltage is too low, then it needs charging, you can do that by using a portable battery charger or jumping the car off of another car’s battery.
Take Your Car to a Mercedes Dealer/Independent Garage
If the battery voltage is good then the problem could be something more complicated like the ignition switch and difficult to fix on your own.
If this is the case, I recommend taking your car to a Mercedes dealer or independent garage for a diagnosis. They will be able to run tests on your vehicle’s electrical system and let you know what is wrong with it.