Mercedes Won’t Start But Lights Turn On

Whenever an issue occurs with a Mercedes, it is annoying. But the frustration is heightened when your Mercedes won’t start but lights turn on.

If your Mercedes turns over but won’t start, and the lights go on when you turn the key, there may be a few possibilities of why it happens. Most of the time, these problems can be fixed.

But if you don’t know what to look out for, tests can be a bit difficult to run. In this brief guide, we will look at the common reasons your Mercedes won’t start but lights turn on. And how to fix it.

Causes and Solutions for Mercedes Won’t Start But Lights Turn On

It’s the kind of problem where your Mercedes won’t start, but the lights come on, and you can hear the fuel pump won’t turn on and clicking. And, if you’re reading this, you’re probably having a great day.

It’s important not to get frustrated because the problem can be very vexing to diagnose. To start with, you have electrical items that appear to work, but the car won’t fire up.

Here are a few things that might be the causes and some solutions to have you back on the road.

1. Battery Issues

The lights might come on, but there might not be enough power from the battery to start the vehicle. The system requires more power to start the engine than is stored by the battery.

Although the battery supplies power to the lights and other electrical components, it might not be able to provide the cranking power necessary to get the vehicle started.

Solution

Test the battery with a digital multimeter or a battery tester. If it’s below 12.4 volts on a fully charged battery and 11.4 volts on a battery with a load, you might want to replace it. Look for loose or corroded battery terminals and clean them right away.

2. Faulty Starter Motor

The starter motor cranks the engine. If it isn’t working, you may hear a click or nothing at all when you turn the key.

The bulbs coming on tell you your battery is fine. Maybe there might be a problem at the starter, it’s not engaging.

Solution

If you hear a click and the engine doesn’t turn over, the starter motor may be defective, and you will need to replace or repair it with modern technology by the help of a car mechanic.

3. Ignition Switch Problems

The power from the ignition switch goes to the starter motor, and if the ignition switch is at fault, the car won’t start, even if all the electrical systems appear to work fine.

Solution

Turn the key to the ‘on’ position, then turn it to the ‘start’ position a few times. If you suspect the ignition switch is the problem, have it inspected and replaced by a professional. 

4. Fuel Delivery Issues

If your Mercedes doesn’t get gas, it won’t start. A dirty fuel filter, a bad fuel pump, or an empty gas tank are possibilities.

Solution

Look at the fuel gauge to see if there’s enough petrol in the tank. If the tank has fuel and the car still can’t start, have the fuel filter and pump checked for problems.

5. Neutral Safety Switch

An automatic transmission does not allow the car to start unless it is put into park (P) or neutral (N). If the neutral safety switch is bad, this might be preventing your car from starting.

Solution

Put the gear shift lever firmly in the “Park” position. If the engine still doesn’t start, the neutral safety switch could need adjustment or replacement.

6. Security System Issues

Today’s Mercedes cars have complex anti-theft systems. If one of these systems malfunctions, the car may not start.

Solution

If any security warning lights are illuminated on the dashboard, check these first. If the problem persists, check the owner’s manual supplied with the vehicle for advice on how to proceed.

7. Fuses and Relays

Fuses and relays are fundamentally important in all electrical systems around your car. A blown fuse or faulty relay might also affect the starting system.

Solution

Go to the fuse box and check for blown fuses or faulty relays. Replace any faulty fuses or relays and see if that resolves the issue.

How To Avoid Mercedes Won’t Start But Lights Turn On

The lights turn on but Mercedes won’t start this is probably a headache for a car owner. No one want such type of problem any more. So, to avoid this problem follow the underneath preventive measures.

Regular Battery Maintenance

Check Battery Health: Check the battery level or simply look for the rosette to spot a build-up of corrosion on the terminals.

Battery Testing: Get your battery tested regularly, especially just before winter and long trips. A good battery reduces the risk of a surprise battery failure. 

Routine Vehicle Inspections

Starter Motor And Ignition System: Check in every week or two with the starter motor and ignition system: although it sounds obvious, paranoid early detection of symptoms that might eventually lead to starting failure will save your head.

Fuel System Maintenance: Follow the maintenance schedule and replace the fuel filter whenever it is recommended. Make sure to fuel the vehicle regularly and check if it has a reliable fuel pump to avoid fuel delivery trouble.

Monitor Electrical Components

Check the Fuses and Relays: By regularly checking and replacing blown fuses and faulty relays, you can avoid electrical problems that could affect the starting system.

Don’t Overload Electricals: Do not overload your electric system by running too many accessories or components at once.

Address Security System Issues

System Diagnostics: Periodically have your anti-theft and security systems checked by a professional to make sure they’re working correctly so as to prevent issues related to a malfunctioning security system.

Correct Key Usage: Only the manufacturer’s recommended keys should be used and not ‘skeleton’ or copy or other types of keys that didn’t originate with the actual security system because these will cause errors in your security system.

FAQs On Mercedes Won’t Start But Lights Turn On

Conclusion

Perhaps it has fuel system, ignition, electrical system generator, or even cooling system problems. Diagnosing the actual, underlying fault that has prevented the car from starting depends on running through a combination of checks.

In most cases, you’ll be able to track down the fault yourself and fix it yourself. On the other hand, if you are not technically minded or you would feel more comfortable taking your car to a professional mechanic than diagnosing it yourself, by all means, do so.