BMW M5 Forum and M6 Forums banner

1 - 20 of 34 Posts

·
Registered
Joined
·
75 Posts
Discussion Starter #1
(My e60 m5 has a Brand new 105aH AGM battery that was installed and registered properly)

As of last few days i’ve been having these on and off symptoms even with 100 amps being shown on the red alternator cable and battery fully charged:

HUD flashing on and off
  • Battery drain in the mornings
  • DSC malfunction notifications
  • “Check battery terminals” error (only once)
  • On and off recharging of battery from the alternator cable — when i start up the car it sometimes shows 0 amps coming from alternator cable with my multimeter. I have to restart the car with the AC turned on to finally get around 70 to 100 amps. the battery can even be nearly drained and still get 0 amps from alternator
Can this be from a bad ground?
 

·
Moderator
Joined
·
1,743 Posts
Overvoltage typically comes with errors that will tell you so. Do you have ista/inpa? If not you should get it at this point.
 

·
Registered
Joined
·
5,959 Posts
Voyage regulator is a common failure point on these cars. My first lasted 70,000ish miles. Replaced the alternator and regulator — everything has been good for the past 100,000 miles.
 

·
Registered
Joined
·
75 Posts
Discussion Starter #7
Voyage regulator is a common failure point on these cars. My first lasted 70,000ish miles. Replaced the alternator and regulator — everything has been good for the past 100,000 miles.
gotcha. Did you get IBS communication codes too on top of the Alternator communication codes?

Just bought a new Valeo alternator for $115 from the “used” (returns) section of Amazon
 

·
Registered
Joined
·
5,959 Posts
gotcha. Did you get IBS communication codes too on top of the Alternator communication codes?

Just bought a new Valeo alternator for $115 from the “used” (returns) section of Amazon
I can’t remember. I replaced it back in 2012/2013. I think I had a code, replaced the IBS cable. Then, subsequently replaced the alternator/regulator thereafter, but it was so long ago.
 

·
Registered
Joined
·
241 Posts
Just a question, does a new voltage regulator come with the alternator when replaced or are they always 2 separate parts on this car?

Sent from my Moto Z (2) using Tapatalk
 

·
Registered
Joined
·
5,959 Posts
The voltage regulator is separate from the alternator. I replaced both as elective/preventive maintenance.
 

·
Registered
Joined
·
75 Posts
Discussion Starter #11
I think what hes asking is if you have to replace the voltage regulator separately When installing new alternator.

new alternators already come with new voltage regulators attached to it. its common for voltage regulators to go bad on the remanufactured alternators though because they dont change them and hard to spot a bad one
 

·
Registered
Joined
·
241 Posts
I think what hes asking is if you have to replace the voltage regulator separately When installing new alternator.

new alternators already come with new voltage regulators attached to it. its common for voltage regulators to go bad on the remanufactured alternators though because they dont change them and hard to spot a bad one
Yes exactly. So if I buy a remanufactured alternator, good chances the voltage regulator is old and will probably need to be replaced as well, but if I purchase a new alternator from BMW both the alternator and voltage regulator will come together and be new right? Thanks for the help.

Sent from my Moto Z (2) using Tapatalk
 

·
Registered
Joined
·
75 Posts
Discussion Starter #13
Yes exactly. So if I buy a remanufactured alternator, good chances the voltage regulator is old and will probably need to be replaced as well, but if I purchase a new alternator from BMW both the alternator and voltage regulator will come together and be new right? Thanks for the help.

Sent from my Moto Z (2) using Tapatalk
i was going to originally do this: buy a cheap remanufactured alternator from ebay ($80) Or Autozone and replace the regulator with a new $50 voltage regulator From Autohausaz.com

heres a link to guy with $80 alternator (use “make offer” option) on ebay... says he only has 10k miles on it. 06-10 BMW E60 E63 E64 M6 M5 S85 170A Engine Newer Alternator Duralast A11262 | eBay

thats if you dont want to spend alot.
 

·
Registered
Joined
·
5,959 Posts
Yes exactly. So if I buy a remanufactured alternator, good chances the voltage regulator is old and will probably need to be replaced as well, but if I purchase a new alternator from BMW both the alternator and voltage regulator will come together and be new right? Thanks for the help.

Sent from my Moto Z (2) using Tapatalk
Yes. Sorry for my confusion. Lots of people just swapped a new voltage regulator with their old alternator. I swapped the entire unit as I wanted zero miles on both.

I think there used to be a DIY in the Board.
 

·
Registered
Joined
·
75 Posts
Discussion Starter #15
Yes. Sorry for my confusion. Lots of people just swapped a new voltage regulator with their old alternator. I swapped the entire unit as I wanted zero miles on both.

I think there used to be a DIY in the Board.
Is it alot faster to just replace the alternator from the bottom? Most guys in thay DIY thread were talking about doing it from the top with only removing the fan shroud... but they kept saying it took them like around 4 hours — which makes me think its alot harder to do it from the top. Was thinking to just buy a $50 car ramp... sounds more straight forward that way
 

·
Registered
Joined
·
187 Posts
Is it alot faster to just replace the alternator from the bottom? Most guys in thay DIY thread were talking about doing it from the top with only removing the fan shroud... but they kept saying it took them like around 4 hours — which makes me think its alot harder to do it from the top. Was thinking to just buy a $50 car ramp... sounds more straight forward that way
You definitely want to do it from the bottom, no need to remove radiator or anything else...maybe the front sway bar


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
2,226 Posts
its not the most fun job. I did it over a weekend as to not rush and a couple times I got frustrated and walked away for a bit. I've never replaced an alt on any car so this was my first....and obv first on an M5. If you are patient and take your time like I did you can DIY....oh and its a bottom side swap. There is a how-to on here somewhere I used to help out
 

·
Registered
Joined
·
75 Posts
Discussion Starter #18
its not the most fun job. I did it over a weekend as to not rush and a couple times I got frustrated and walked away for a bit. I've never replaced an alt on any car so this was my first....and obv first on an M5. If you are patient and take your time like I did you can DIY....oh and its a bottom side swap. There is a how-to on here somewhere I used to help out
Are there instructions on tightening and replacing the belt afterwards? I wonder if i should even bother with a new belt at 56k miles
 

·
Registered
Joined
·
2,226 Posts
There is a how-to on here if you do a search you should be able to find it. It has pics and whatnot. I think I posted in the thread too. Anyway there is a tensioner nut you need to pull back on to get slack to slip the belt off the smooth pulley so it gives you enough slack to pull it off the alt. You'll need a breaker bar to get enough leverage....also helps if you have another set of hands for the belt/tensioner part....and to hold the alt up when trying to mount etc. I didn't replace my belt. 40k on the car.
 
1 - 20 of 34 Posts
Top