E90Post
 


 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Technical Forums > Mechanical Maintenance: Break-in / Oil & Fluids / Servicing / Warranty > Voltage Regulator? Battery? Alternator? How To/Diagnosis



Reply
 
Thread Tools Search this Thread
      04-23-2015, 08:44 AM   #1
Farroar
New Member
0
Rep
9
Posts

Drives: 2007 335xi black sapphire
Join Date: Jan 2012
Location: Colorado

iTrader: (0)

Voltage Regulator? Battery? Alternator? How To/Diagnosis

Hey folks,

I've been searching for info on how to properly diagnose the source of a battery related issue and I've found a lot of info here an there but not much about how to differentiate between the above topics. The Bentley manual doesn't give much info on these items really.

I have been having an issue with my car that has been pretty benign until recently. Really cold day a couple months back I couldn't start my car. It was like -20F. Had it jumped and didn't think much of it. Was sitting in my car having lunch and listening to the radio with engine off... car wouldn't start. Had to get it jumped again. That was a month ago. Now, the car won't start without a booster. All lights power up fine and the little battery icon doesn't even pop up on the display. Just won't start.

So this got me to thinking as the battery isn't that old.

How do I differentiate between alternator, battery, and power regulator?

What are the best ways to test each for correct functionality?

I have the INPA software and can mess with that a bit but wanted to see if I could get some parameters that I need to check.

I did check voltage at the battery when the car was on and off and it seemed to be off of what was listed in the Bentley. That is said to point to a regulator issue but I'm not convinced. So, before I go nuts on replacing parts I'd like to see if there is a good breakdown for each component. Could be a combination I suppose.

Thanks!
Appreciate 0
      04-23-2015, 09:12 AM   #2
KeepRidingDirty
Professional Monkey Trainer
KeepRidingDirty's Avatar
Canada
13
Rep
300
Posts

Drives: 2007 BMW 335xi
Join Date: Aug 2014
Location: Ottawa, On

iTrader: (1)

Quote:
Originally Posted by Farroar View Post
Hey folks,

I've been searching for info on how to properly diagnose the source of a battery related issue and I've found a lot of info here an there but not much about how to differentiate between the above topics. The Bentley manual doesn't give much info on these items really.

I have been having an issue with my car that has been pretty benign until recently. Really cold day a couple months back I couldn't start my car. It was like -20F. Had it jumped and didn't think much of it. Was sitting in my car having lunch and listening to the radio with engine off... car wouldn't start. Had to get it jumped again. That was a month ago. Now, the car won't start without a booster. All lights power up fine and the little battery icon doesn't even pop up on the display. Just won't start.

So this got me to thinking as the battery isn't that old.

How do I differentiate between alternator, battery, and power regulator?

What are the best ways to test each for correct functionality?

I have the INPA software and can mess with that a bit but wanted to see if I could get some parameters that I need to check.

I did check voltage at the battery when the car was on and off and it seemed to be off of what was listed in the Bentley. That is said to point to a regulator issue but I'm not convinced. So, before I go nuts on replacing parts I'd like to see if there is a good breakdown for each component. Could be a combination I suppose.

Thanks!

Sounds like a dead battery. I would throw a battery charger on it overnight. If you have a situation where you can't start it again I would say battery.

You can throw a multi meter on it while running. You should be seeing around 14 volts. If you're seeing 14 volts Your alternator and voltage regulator are fine (voltage regulators are usually built into the alternator, not sure how the IBS works on this car though).

These cars take a lot of voltage and need to have a charger thrown on them once every few months, especially in cold weather.
__________________
JB4 G5 ISO / ER Charge Pipe and Tial BOV / Wagner FMIC / CYBA Tips & Air Scoops / AFE DCI / BMW PE Exhaust Mod / M3 Rep Bumper / Dynavin E9x
Appreciate 0
      04-23-2015, 09:34 AM   #3
Farroar
New Member
0
Rep
9
Posts

Drives: 2007 335xi black sapphire
Join Date: Jan 2012
Location: Colorado

iTrader: (0)

Thanks for the info. So, testing at the battery while running is measuring the voltage that the alternator is putting out? If I were to test the same location while the car is not running, that would show me the output from the battery I'd assume.

If the car is revving to say 2K while testing at the battery, I assume that the 14 volts should maintain? If it does fluctuate does this point to an issue with the alternator?

Lastly, what's IBS?

Thanks!
Appreciate 0
Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -4. The time now is 03:56 PM.




e90post
e90post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST