Hi all, 2007 E83 3.0D LCI
Issue is that the alternator is not charging the battery.
New alternator fitted - no difference
Known good battery off my VW diesel put on to the BM, no difference
Tried disconnecting the battery monitoring sensor to see if that had any effect - no
No codes showing up and when I look at live data it shows the alternator running at 99% load and the battery voltage slowly drops as the car runs.
Starts perfectly off a charge battery, battery light is on the dashboard before starting and immediately goes out when the car starts up.
This is doing my head in so if anyone has any ideas, I'd appreciate your assistance.
Thanks.
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Battery not charging.
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GT456!
- Member
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- Joined: Mon Jul 24, 2023 3:19 pm
Battery not charging.
[glow]Only because I've just completed an episode with the alternator I'll have my experience to offer.[/glow]
A new alternator or a new to you alternator? I had a used alternator on the shelf when my existing alternator became suspect. Changed it out no problem! Yes problem! After research discovered problem was likely the regulator...then ordered a Bosch regulator (a must!) waited a week for delivery. Installed the Bosch regulator...no smooth idle the m54 is known for the smooth idle noway I Could settle for less. More research discovered the regulator has these 2legs that ride on these 2 slip rings (these two small rings spin) inside the alternator housing only way to get a visual is to remove the regulator watch out for removing the screws that hold the regulator they can strip Phillips head or can be t20 torx? Don't try to be like me and remove the regulator while alternator is installed...do the de+install.
Moving right along... remember the question, is the alternator just new or new to you/used...if used... remember the slip rings,,,those rings can get dirty from all those rotations on the legs of the regulator.
So dirty that it can cause problems with the alternator communicating with the cars ECU resulting in misfires and a steady idle and who wants and needs an unstable idle trust me!
Major point
no need for a used alternator if the internal slip rings are corrupted from natural ware from the slip rings! So the result for me was to order a new alternator (06 e83 had 240k on the clock)...then what came in to question was the alternators regulator to save $$ the alternator will come with a regulator but not oem...and it is possible that the setup as with most aftermarket products the housing or securing screw holes may not match oem Bosch...I stopped holding my breath when I installed the Bosch regulator inside the aftermarket alternator! It fit! Now I have an aftermarket alternator that can talk to the ECU in the bmw language. How did we come to the conclusion of all these replacements...reading the DTCs.
Tell me does 281c or d appear in your scanner results?
A new alternator or a new to you alternator? I had a used alternator on the shelf when my existing alternator became suspect. Changed it out no problem! Yes problem! After research discovered problem was likely the regulator...then ordered a Bosch regulator (a must!) waited a week for delivery. Installed the Bosch regulator...no smooth idle the m54 is known for the smooth idle noway I Could settle for less. More research discovered the regulator has these 2legs that ride on these 2 slip rings (these two small rings spin) inside the alternator housing only way to get a visual is to remove the regulator watch out for removing the screws that hold the regulator they can strip Phillips head or can be t20 torx? Don't try to be like me and remove the regulator while alternator is installed...do the de+install.
Moving right along... remember the question, is the alternator just new or new to you/used...if used... remember the slip rings,,,those rings can get dirty from all those rotations on the legs of the regulator.
So dirty that it can cause problems with the alternator communicating with the cars ECU resulting in misfires and a steady idle and who wants and needs an unstable idle trust me!
Major point
no need for a used alternator if the internal slip rings are corrupted from natural ware from the slip rings! So the result for me was to order a new alternator (06 e83 had 240k on the clock)...then what came in to question was the alternators regulator to save $$ the alternator will come with a regulator but not oem...and it is possible that the setup as with most aftermarket products the housing or securing screw holes may not match oem Bosch...I stopped holding my breath when I installed the Bosch regulator inside the aftermarket alternator! It fit! Now I have an aftermarket alternator that can talk to the ECU in the bmw language. How did we come to the conclusion of all these replacements...reading the DTCs.Tell me does 281c or d appear in your scanner results?