Twist the tensioner bolt counterclockwise and reposition the serpentine belt.
Reconnect the battery.
Start the engine and check voltage. With the engine running, you should be getting between 14.0 and 14.7 volts.
Frequently Asked Question
How do you know your alternator is bad?
A common symptom of a defective alternator is when your battery light is on while the engine is running.
How much does it cost to replace a Mercedes Benz Alternator?
The average cost to replace a Mercedes Benz Alternator is between $447 and $800. Labor costs are estimated at around $386, while parts are priced between $350.
How long does a Mercedes Benz Alternator last?
The average life span of an Alternator is about 6 to 10 years. It depends on how many miles the vehicle is regularly driving and how many aftermarket accessories the owner have installed, which may cause the alternator to work overtime.
How to test an alternator?
Using a voltmeter, connect your positive lead to the battery's positive terminal and negative lead to the battery's negative terminal. It would be best to get 14 v to 14.8 v, which means your alternator is working properly.
Can you drive a Mercedes with a faulty alternator?
It is not recommended to drive the car once the check battery light is on since it is more likely that the car would stall after a few minutes.
Mercedes-Benz vehicles are equipped with an M273 engine.
2004–2011 R171 SLK 350
M272 IN SLK R171.jpg
2004–2010 W219 CLS 350
2005–2010 C209 CLK 350
2005–2007 W203 C 350
2007–2011 W204 C 350 / C 350 4Matic
2011–2015 W204 C 350 BlueEfficiency / C 350 4MATIC BlueEfficiency
2005–2009 W211 E 350 / E 350 4MATIC
2009–2011 W212 E 350 / E 350 4MATIC
2005–2013 W221 S 350
2005–2012 R230 SL 350
2006–2017 W251 R 350
2006–2011 W164 ML 350
2005–2014 W639 Viano (known as the M272 978 in China)