In this guide, you will learn how to replace the Alternator on a Mercedes E C CLK S ML GL R Class with the M272 and M273 engines.
- Battery warning light stay
- Engine stalls.
What you will need
- Park vehicle on level ground and set the parking brakes.
- Allow the engine to cool down.
- Pull the hood release under the dashboard and open the hood.
- Disconnect the battery.
- Create a diagram of how the serpentine belt is routed on the different pulleys.
- Loosen the serpentine belt by using a 17mm socket to twist the tensioner bolt counterclockwise.Slide the belt off it.
- Remove the alternator ground wire using a 12mm socket.
- Loosen four (4) alternator retaining bolts using an E12 socket.
- Unplug the alternator electrical connector from the back of the alternator.
- Remove the alternator.
- Position the replacement alternator.
- Connect the alternator positive cable and electrical connector.
- Connect the negative connector using a 12mm socket. Re-attach the rubber cap(if any).
- Mount the alternator using 4 retaining bolts.
- Twist the tensioner bolt counterclockwise and reposition the serpentine belt.
- Reconnect the battery.
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.
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 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)
- 2006–2013 NCV3 Sprinter
- 2008–2011 CL203 CLC 350
- 2008–2012 X204 GLK 350
- 2006–2011 E 500 / E 550
- 2006–2010 CL 500 / CL 550
- 2006–2010 CLS 500 / CLS 550
- 2006–2012 GL 500 / GL 550
- 2008–2011 ML 500 / ML 550
- 2006–2009 S 500 / S 550
- 2007–2012 SL 500 / SL 550
- 2006–2009 CLK 500 / CLK 550
- 2006-2015 G 500 / G 550
- 2007–2012 GL 450
- 2007–2013 S 450
- 2007–2011 ML 450
DIY Cost: $100-$250
Est. Time: 2 hr