Mercedes Won’t Start? Here’s Quick Solutions to the Most Common Causes

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Let's face it, we've all experienced it, you've got places to be, you get in your Mercedes, turn the key, and … drum roll please … nothing at all! Your Mercedes wont start! This an incredibly irritating circumstance, but do not fret, we've got you covered. There are lots and lots of reasons why your Mercedes wont start, and within this guide, to spare you time we'll go over the most typical factors as well as give you useful solutions to get your car back on the road ASAP!

If you're limited by time, rather than reading, you’re always welcome to speak to a live mechanic 24×7 and get immediate help and assistance on figuring out what it is and fixing the problem, by clicking the “ask a mechanic” button in the bottom right of this page.

Understanding the Problem

Car Won't Start?

Before we get stuck into the causes and repair options it's important to first comprehend the problem. When you realize to yourself “my Mercedes won't start”, this could be due to different things being wrong with your car. Possibly the engine is not turning over at all, possibly it is cranking partially however then not starting, or perhaps it's making a clicking noise when you try to start the engine, but ultimately absolutely nothing happens. Each of these cases can indicate various issues with your car.

Common Reasons Why Your Mercedes Won't Start

There are numerous contributing reasons why a Mercedes will not start up. These issues usually include a dead or weak vehicle battery, a bad alternator, starter motor failures, fuel system issues, along with electrical or circuitry concerns. Each one of these problems can manifest as a multitude of symptoms and require different solutions to detect and resolve, so we can get your car back on the road ASAP.

Symptoms of a Mercedes That Won't Start

Having the ability to recognize and diagnose these symptoms, will assist you in finding the root cause of the issue. For example, when you turn the key in the ignition, and you hear a clicking sound but your Mercedes still wont start, it is often an indication that there is a problem with the fuel or ignition system of your car.

Analysis of The Reasons Why Your Mercedes Won't Start

The initial step to finding a solution to the problem is having a grasp of the root cause of that issue, so let's look into the most typical factors why your Mercedes fails to start.

Mercedes Battery Issues

Auto mechanic replacing car batteryIn the majority of instances, the most common reason why your Mercedes fails to start is often due to the battery, it's either weak or dead, and you have to charge your car’s battery or replace it. The car's battery provides the electric required to start the engine, and power all the electrical parts in your Mercedes. Signs of a bad battery issue in a Mercedes, can be things like the car being slow to crank the engine, weak or dim headlights, or a lit-up battery alert light on the dash

Mercedes Alternator Problems

is my alternator stopping my car from starting?

The alternator is responsible for charging the battery from the engine while the car is running. A faulty alternator can certainly prevent your Mercedes from starting as it won't have the ability to charge the battery, from the engine, so it will deplete all the way down until it's totally dead and you only realize it when you get in your Mercedes and it won't start. Symptoms that the alternator may be faulty include a lit up battery or alternator warning light on the dash, weak or dim headlights when the engine is idling, and also a whining or grinding noise from the engine while its running.

Mercedes Starter Motor Failures

my car wont start is the starter motor?

When you start your Mercedes, the starter motor deals with turning the engine over (cranking it). If the starter motor is broken in some manner then the engine won’t crank, and your Mercedes won't start. You can find out if your starter motor has a problem or not usually by listening, if you hear a clicking noise when you turn your key or a grinding noise during the startup, or your car starts up but only intermittently, then the starter motor may very well be the problem.

Mercedes Fuel System Complications

my car wont start but clicks

We’re not talking about when you just run out of gas here, but the fuel system itself having complications. Your Mercedes uses a combustion engine, and therefore to start and run, it needs a combination of both fuel and air. If your Mercedes problems are because of a faulty fuel system, this can sometimes be a clogged fuel filter or a faulty fuel pump relay, which could mean the engine might not be receiving the fuel it requires to get the car started.

Mercedes Electrical System or Wiring Problems

can electrics be a reason a car wont start

Modern Mercedes's rely heavily on electronics, which can mean there are lots of things that can potentially break. Even in an older vehicle, you can have typical issues such as blown fuses, spark plug problems, a damaged ignition switch, or a broken sensor and more. These can be a few of the various electrical reasons your vehicle can't start. Indications of a wiring or electrical problem can differ widely but can typically include the engine not cranking, or your Mercedes can start however just intermittently or some warning lights show on the dashboard. To correctly identify and repair these kinds of issues, you will need the skills of an experienced car mechanic locally or online.

Solutions & Repair Tips

When you have figured out what the reason for your Mercedes being unable to start is. The next logical step is obviously to try and fix it. Here are some pointers for the common problems we've covered previously.

How to Troubleshoot and Fix Battery Issues in a Mercedes

my car wont start i think its the battery

If you suspect it's possible a battery issue is a reason why your Mercedes has trouble starting, then the first thing you must do is check the battery terminals. You want them to be clean, not corroded, and firmly connected. If you discover that the terminals are corroded you can try to clean them up with a mix of baking soda and water. You will need to replace the battery if it's old or weak, otherwise even if you charge it up enough to start the vehicle, it will likely deplete quickly once again in the near future. You can make use of a multimeter as a battery tester to find out if it’s worth saving or if it needs replacing. You can ask a reliable car mechanic online or locally to best advise you on this.

How to Diagnose Alternator Problems in a Mercedes

car wont start, jumped and started alternator

If the alternator is what you suspect is the perpetrator, you can test it. If you can get the vehicle started temporarily (you may need to jump-start the car for that), but once it’s going, let the car run, and while the engine is running, disconnect the positive terminal of the battery. It's likely due to a fault with your car's alternator if you notice that your Mercedes dies instantly when you disconnect the positive terminal. You should be aware however that this method can be dangerous, and may damage the sensitive electronic elements in your Mercedes, so it's necessary to seek advice from a professional car mechanic locally or online, before ever attempting this.

How to Identify Starter Motor Failures in a Mercedes

car wont start starter and battery good

If you suspect the starter motor is the cause of your Mercedes not starting, listen for a clicking noise when you turn the ignition key. In these cases, the solution is to have the starter motor changed for a new one by a professional mechanic.

How to Fix Fuel System Complications in a Mercedes

clogged fuel filter car wont start

If you think the issue is due to a fuel system problem, try and listen for the fuel pump when you turn the key to the “on” position, before starting the car. You ought to hear a humming noise for a couple of seconds. If you are unable to hear this sound, then it might be there is cause for concern with the fuel pump. If you discover your Mercedes is tough to start, it stalls, or it has weak acceleration, it might be a result of a clogged fuel filter. Both of these will likely require a reliable car mechanic in order to effectively fix.

How to Repair Electrical or Wiring Problems in a Mercedes

fuses to check when car wont start

If you think it's a wiring or electrical system problem, first check the fuses associated with the ignition system, and change any that have blown. If your Mercedes starts after this, then it was an effective, simple, and low-cost repair! If the car does not start, even intermittently, it might be an issue with the ignition switch itself. It could be a faulty sensor if numerous warning lights are visible on your dashboard. These problems can be extremely complicated and a professional car mechanic is likely required to diagnose and have it properly repaired.

Preventive Steps

As my father always stated “Prevention is better than cure”, so here are some preventative measures to ensure you avoid any Mercedes starting pains again!

Regular Maintenance of Your Mercedes:

Regular maintenance on car to prevent starting issues

Regular upkeep of your Mercedes is key to preventing future troubles. This consists of things like routine oil changes, inspecting the battery, cleaning the terminals, replacing the fuel filter as advised/required, and of course having your Mercedes examined by a reliable car mechanic regularly. If you are not sure about the regular upkeep tasks needed for your specific vehicle, you can consult a mechanic in your area or online.

Drive Your Mercedes Frequently:

drive regular to avoid car troubles

If you happen to leave your Mercedes stagnant for long periods of time without driving it, the battery can waste out of charge as it's not getting any charge from the engine being used. Try your best to drive your vehicle regularly to keep the battery charged. Take it for a fast spin to make sure there is still a charge in the battery if you remember you have not driven your Mercedes in a while. Worth noting: letting the battery fully drain, is also damaging to the longevity of the battery, try not to do this.

Pay Attention to Warning Signs:

Check Engine Control Light on a Vehicle Dashboard

If you observe anything odd like unusual sounds, changes in driving and performance, or warning lights are now visible on your Mercedes's dashboard, don’t just ignore them. These are usually early indications of a problem and it’s best to be addressed ASAP so that they don’t become larger issues down the line. Speak with a car mechanic locally or online about these warning lights and get advice on if they need to be attended to.

When to Ask a Mercedes Mechanic Online

If you want to save time, want a professional Mercedes mechanic on hand to guide and advise you, or you have tried to resolve it for yourself, however in spite of your best efforts your vehicle won't start, then talking with a Mercedes mechanic online can be a terrific option.

Advantages of Online Mechanic Solutions

Happy mechanic repairing car looking at camera

Online mechanic services, like ours in the bottom right of this page, provide several advantages. You can get expert Mercedes mechanic guidance 24×7 and without leaving your house, which is especially beneficial if your vehicle will not start and is stuck in the driveway. It can also help you save money as online mechanic consultations are more affordable than a physical visit to a local mechanic near you. Plus, you can get the answer quickly, which is great if you're in a rush, require a second opinion, or you simply prefer having an expert Mercedes mechanic on hand.

How Services Like Can Help You

Ask a mechanic online about my car not starting connects you with licensed professional mechanics who can provide instant aid, guidance and advice. You have the ability to describe the problems you are having with your car, ask a Mercedes mechanic limitless questions, and even submit pictures and videos so you are able to show the mechanic what you mean. You can speak with them via online chat or by telephone call, whichever you choose. The Mercedes mechanic will help you identify the problem, advise you on the best course of action for your individual circumstance and even guide you through easy maintenance and repair work every step of the way.


In conclusion, when your Mercedes won't start, it will likely be a major bummer and an enormous hassle. However, having a firm grasp of what might be causing the problems, having the ability to troubleshoot them, and knowing what steps are required in each case, and where to get help if required, will be a big help. Bear in mind that routine upkeep is essential for preventing the vast majority of vehicle issues.

Even if this piece was helpful but your car still doesn't cooperate, remember to ‘ask a mechanic for free‘ via our service.

Frequently Asked Questions (FAQs)

What should I do if my Mercedes doesn’t start? 

Firstly, don't panic. Try to identify any signs that might indicate an issue, such as unusual noises, warning lights on the dash, or changes in performance. The cause of the problem is likely among the most common causes talked about in this guide. If you can't find the issue yourself, you will need the assistance of a Mercedes mechanic locally or online.

How to tell if my Mercedes wont start because of the battery?

Indications of a battery issue in a Mercedes consist of the engine being slow to crank, dim headlights, and lit battery warning lights on dash. You can also check the battery terminals to see if they are clean, not corroded, and securely connected. If the battery is weak or old, it might be best to just swap it for a newer one.

How can I prevent my Mercedes not starting issues?

In order to ensure this inconvenience never ever happens once again, regular upkeep is essential. This includes things like oil changes, inspecting the battery and cleaning it's terminals, changing the fuel filter as recommended / required, and having your Mercedes inspected by a mechanic routinely. It's also a fantastic idea to drive the car routinely so the battery remains charged.

Can I ask a mechanic online if my Mercedes will not start? 

Yes, you can. An online mechanic service like ours can provide instantaneous specialist Mercedes mechanic assistance and advice, without you needing to leave your house. If your Mercedes wont start and is stuck in the driveway, this is especially beneficial.

How can services like help if my Mercedes wont start?

We connect you with accredited expert Mercedes mechanics who can offer suggestions on your particular circumstance. You can tell them about your car problems, ask unlimited questions, and even upload images and videos so you can effectively describe and show the problem. The mechanic will have the ability to help, troubleshoot, diagnose the problem, suggest the very best course of action and guide you along the way.

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