How to use a multi-meter to check fuses on any Mercedes-Benz

Introduction

Step-by-step guide on checking, testing, and replacing fuses in any Mercedes-Benz. If a component in your car is not working, such as the radio, cigarette, auxiliary outlet, power seat, windows, or other electrical units, you should first check the fuses.

How to check the fuses using a multimeter

Use this guide to check the main fuses located in the engine compartment or the interior fuses on the dashboard side. Using a multimeter to check the fuses is easy and fast. You don’t need to remove fuses individually or use a fuse puller or needle-nose pliers.

You will need a digital multimeter that can perform the continuity check. If you don’t have one, consider any of the Top 10 Best Selling Digital Multimeters on Amazon. Just make sure that it provides an audible continuity check.

Instructions on how to check the fuses

Using this method, you can test mini fuses, glass tube fuses, standard blade fuses, or maxi fuses. This video shows you how to use a Mastech MS8229 Multi-functional digital multimeter to test the fuses. 

Step-by-step instructions on how to test fuses on a Mercedes-Benz

Locate the fuse panel in your car. On most Mercedes-Benz cars, there is more than one fuse panel. The common location of the fuse panels is under the hood, side of the dashboard, or in the trunk.

• Turn the multimeter on.

• Turn the knob on the multimeter to the ohm setting. Some multimeters have a separate setting for continuity checks.

• Next, press the SELECT button until a small speaker symbol appears on the display. 

• Test the multimeter by touching the two probes together. If it’s working, you should hear a beep.

• Now, press the probes firmly at the end of the fuses to make contact with the two metal posts.

• Check the fuses by touching the two probes on each side of the fuse. If the fuses are good, you should hear a beep.

• If you don’t hear a beep, you have blown a fuse.  

Always replace a blown fuse with a new one of the same type, color, and amperage rating.

How to check fuses using a test light

To check fuses using a test light, we recommend using an LED test light. LED test lights draw very little current and are safe to use for checking voltage at the fuse box. They work great for finding the 12-volt source or testing power on different equipment. Our recommendation would be Innova Smart Test Light. The Innova has a white test light that is useful to shine on the area you are working on and indicate that you have connected the test light properly. Connect the test light to the battery terminals or the cigarette lighter. Turn the ignition to position II. Connect the test light probe to both sides of the fuse. You should see the red light turn on when you contact both terminals of the fuse. 

Where to buy replacement fuses?

If you have blown fuses and need to replace them, the most cost-effective way is to purchase new ones on Amazon. You can get an assorted fuse box with over 100 spare fuses and all ampere ratings you will need for under $20. Here are a few boxes of Assorted Automotive Fuses, over 100 fuses.  

Frequently Asked Questions

What if your multimeter does not have a sound feature?

• Look at the multimeter display to ensure you see all zeros as you test a good fuse. If y you don’t see all zeros, you have a bad fuse.

How does it sound when you have a bad fuse?

• You will not hear a beep when you connect the probes to a bad fuse. The m multimeter screen will NOT display all zeros.

What multimeter should I use to check the fuses?

• While almost any multimeter will complete the job, here are some top-rated multimeters. 

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