How to replace the alternator on a Mercedes Benz.
Step-by-step instructions on how to replace the alternator on a Mercedes Benz
- Open the hood.
- Disconnect the NEGATIVE terminal from the battery. HINTS: Locating the battery. If you have a C / E / CLK class, it could be either in the engine bay compartment, under the rear seats, or in the trunk. We are working on a C Class W203 2001-2007; the battery is in the engine bay. First, we need to remove the cabin air filter housing. Push up the 3 clips in the picture below and pull out the housing.
- Remove the bolt on the NEGATIVE battery terminal clamp and disconnect the cable. You will need to loosen the 10 mm bolt; no need to altogether remove the bolt.
- Remove the engine cover. It comes right up. It has clips that hold it in place and no screws.
- Remove the serpentine belt. Read this article and watch the video on replacing the serpentine belt.
- Remove the cap from the back of the alternator. This is the electrical cable that is part of Circuit 30. The alternator is identified as G2 on electrical schematics.
- You should see a nut. Remove the 13mm nut on the back of the alternator. See the close-up picture below.
- Unplug the connector that goes into the back of the alternator. Press on the tab and pull it away from the alternator.
- Remove the two bolts that hold the alternator in place using the Female E Torx sockets we listed in the required tools section above.
- Remove the alternator. Removing it won’t be easy, but you can do it. You may have to use some force in this process. This step won’t be fun.
- Install the new alternator. Here are some pictures of our new alternator, which we bought for $115 on Amazon. If you need a replacement alternator at a fraction of dealer prices and even cheaper than your local parts store, check out Amazon; click here.
- Install the new alternator and tighten the two bolts to 42 Nm.
- Connect the electrical cable to the alternator. Tighten the nut for the electrical cable ( positive +) between 15-18Nm.
- Plug the electrical cable on the back of the alternator and make sure it clicks when you push it in. That way, you know it is locked in place.
- Reinstall the serpentine belt and the engine cover, and reconnect the battery.
- 2 Bolts that hold the alternator in place. Max 45 Nm.
- 1 Bolt on the back of the alternator. Between 15 Nm to 18 Nm.
How much does a Mercedes Benz alternator replacement cost?
The answer depends on where you live. With that in mind, we will give you a general idea. First is the price of the alternator. If you buy it at the dealer, you can spend around $1000 to replace the alternator. If you do it yourself, you can save hundreds and replace the alternator for 1/10 of that. How?
C Class Models: C240 C320 C32 C280
CLK Class: CLK320 CLK430 CLK55
Related Part Numbers
Bosch Alternator 12 120 Pulley Rotation Polarity
Bosch 0124515046, 0986042550, 0124515132
Chrysler 5097755AA, 5097756AA
Mercedes 0111546802, 011-154-72-02
Mercedes A011-154-68-02, A011-154-72-02
Valeo 2542317, 437222, 542317, SG12B021
Bosch 0-124-515-056, 0-124-515-132, 0-986-047-540
What Scanner Can I Use to Troubleshoot Mercedes-Benz Alternator Problems?
If you’re experiencing problems with your Mercedes-Benz, a YOUCANIC full system diagnostic scanner can help you troubleshoot the issues. This advanced diagnostic tool can read and interpret the fault codes stored in your car’s computer system, providing detailed information about any problems with the engine, transmission, brakes, or other critical systems.
The YOUCANIC scanner can also perform diagnostic tests on various systems, including the ABS, airbag, and steering systems, to help pinpoint the root cause of any issues. With this information, you can make more informed decisions about repairs and maintenance, saving time and money on costly repairs.
Please use the comments section below to let us know how your job went. Feel free to post any recommendations or suggestions to help others.