w211 alternator problems

[parkscon]

Hi I was getting a red battery warning light on my w211 2004 E320 cdi so while I was in mb getting some work done they suggested I needed a new alternator which purchased and installed however after installing it im still getting the same problem can anyone tell me if there is a relay or fuse which controls the alternator if so where?.
kevin

 

[grober]

There are normally two batteries+ a battery control module+isolating relay and other bits and pieces so lots of things to go wrong /flag faults . Sounds as if your auxilliary battery might be on the way out -has it ever been renewed?

 

[parkscon]

thanks graham yes auxiliary battery was changed last year but I can now check out more avenues relay ect thanks once more really helpful info.

 

[parkscon]

update had alternator checked its charging the batteries but still wont let me reset red warning light???

 

[HITECH]

I used to get this when i left the car for 3 weeks at a time when i was away working. I just trickled charged the battery over night and it stopped it. Absolutely no way would i have replaced a perfectly good alternator. I think they have robbed u bud unfortunately. keep driving it and just keep checking ur battery charge level when the car is idling. It WILL go away. Im talking from experience. give it at least 2 weeks to go away completely.

 

[Dec]

Is your car alarm in full working order?

Dec

 

[parkscon]

alarm seems to be working fine have had a look at the car today it seems to be grounding out on pin number 63 of the ecu don't know if that means
anything to anyone?

 

[parkscon]

Hi thankyou everyone for all your help and advise had the car checked at my local indie and my first suspicions were correct I had purchased a duff alternator swaped it with a bosh reconditioned one and all is well
Kevin. :bannana:

 

[John]

Hi thankyou everyone for all your help and advise had the car checked at my local indie and my first suspicions were correct I had purchased a duff alternator swaped it with a bosh reconditioned one and all is well
Kevin. :bannana:

My alternator died at the turn of the year on a 54 plate W211 - so around a decade seems to be a fairly typical life for them... I've heard other incidents of alternators going in this time scale too...

Glad it is sorted. Right PITA with a duff alternator.