Getting behind the wheel of a car that suddenly won’t start can be an infuriating feeling to say it mildly. But don’t despair! Often the cause of your Mercedes-Benz not turning over is relatively simple, a problem that can be fixed without expensive repair fees.
The following troubleshooting guide is designed to help you with these minor Mercedes-Benz ‘no-start’ issues.
Of course, there will be situations in which seeking a professional Mercedes-Benz mechanic is necessary. However, there are a few tests you can perform to avoid those high troubleshooting bills and some preventative maintenance you can do to avoid this situation from occurring again (or even in the first place).
But first, it’s important to note that there are four conditions that allow a Mercedes-Benz to turn over, all of which must be met:
- Start enable by Drive Authorization System
- Electrical power for cranking the engine
- Spark to ignite
- Fuel for running the engine
When Your Mercedes-Benz Won’t Turn Over
1. Check the Battery’s Age & Charge
An old battery is frequently the crux of many a vehicle’s electrical problems — including one that won’t turn over.
Therefore, the first thing to do is to check the charge and age of your current Mercedes-Benz batteries. Some owners have had their units last well over a decade, but most vehicles will need their batteries replaced every 6 to 7 years.
Another battery issue is a low charge. If your Mercedes-Benz will only turn over once or you hear just a few clicks before it stops, then you might be able to fix the issue by just trickle charging your battery with a 12-volt battery charge.
2. Inspect Fuses & Relays
If it’s not the battery, it can still be an electrical issue only one that arises out of a bad fuse or relay. The Starter Circuit, Ignition, EIS, and Fuel Pump are all fuses that impact a Mercedes-Benz’s ability to turn over.
If a fuse blows or burns out, then it can prevent your car from effectively turning over.
You can use a digital multimeter — found at any automotive or hardware shop — to easily and quickly check your vehicle’s fuses. If this is the issue, you can either replace a blown fuse on your own or seek out the assistance of a professional.
3. Fuel System Problems
The most obvious first fuel problem to check is to be sure your vehicle has fuel in it!
This is a common oversight, but one that is thankfully easy to solve. Add a gallon of fuel and try turning your Mercedes-Benz on again.
If it is still having issues, inspect your fuel filter. If it appears clogged, frayed, or otherwise in unkempt condition, then a simple replacing might be what your vehicle needs.
Another fuel system issue may involve the fuel pump and pump relay system. An experienced Mercedes-Benz mechanic should be called in if this is the case.
4. Starter Motor Problems
Starter motors can become defective over time, after which they can prevent an engine from turning over. The first way to troubleshoot this issue is with checking the connecting starter fuse.
Generally, when a starter becomes defective it will blow out the starter fuse in order to protect its circuit. You’ll know it’s the starter motor that’s the problem and not a bad fuse if a replacement fuse blows out shortly after installation.
Depending upon the nature of your starter motor problems, you may be able to get it to work a few times before it will completely stop working -(a good technique to get a few more starts out is to hit it with a rubber hammer a few times while turning the key to the run position).
This can allow you to get everything sorted before taking it to your local Mercedes-Benz mechanic for a complete test, diagnosis, and replacement if necessary.
5. Bad Spark
If your vehicle cranks but doesn’t completely turn over, then your solution may just be a simple spark plug replacement. Spark test tools and spark replacements are relatively inexpensive and can be done readily at home.
For more information about the above troubleshooting steps or to seek more advance vehicle assistance, schedule a visit with our Mercedes-Benz mechanics today.