alternator failure
Thread Starter
Junior Member
Joined: Feb 2013
Posts: 26
Likes: 3
From: New york
W211 E55 AMG
alternator failure
hey mbworld, for some reason my cars alternator keeps failing. this is going to be my 3rd one in the last two months and i can't figure out what is killing them. i had the first one changed by my indy and it was replaced the second time under warranty. its becoming a pain i would just like some feedback from anyone who has had similar issues, or may have a clue as to why this is happening. my terminals are good and the only thing that i have installed on the car that may cause an extra strain on the battery is 2 amps and a 10inch subwoofer that i added to the car. my next step is bringing the car to the dealer as soon as i can this week 
Thanks!
-Shane
Thanks!
-Shane
Junior Member
Joined: Feb 2011
Posts: 50
Likes: 1
2007 E63 AMG
Found this to be helpful in the past....not sure if it applies to the MB application though....Just a thought.
Can you check the voltage difference between the alternator output and the battery positive terminal? Then run a battery load test to work the alternator hard. The voltmeter shouldn't read more than a couple tenths of a volt maximum. If higher, there's a bad connection, or the wire itself is faulty. This would cause the battery to be constantly low on voltage, and the voltage regulator would sense this. That would make the Alternator constantly try to charge the battery up to a level that is difficult to reach, overworking the Alternator, especially when lights and A/C and such are being used.
Also similar readup: http://forums.dieselpowermag.com/70/...ind-the-cause/
Can you check the voltage difference between the alternator output and the battery positive terminal? Then run a battery load test to work the alternator hard. The voltmeter shouldn't read more than a couple tenths of a volt maximum. If higher, there's a bad connection, or the wire itself is faulty. This would cause the battery to be constantly low on voltage, and the voltage regulator would sense this. That would make the Alternator constantly try to charge the battery up to a level that is difficult to reach, overworking the Alternator, especially when lights and A/C and such are being used.
Also similar readup: http://forums.dieselpowermag.com/70/...ind-the-cause/
