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-   -   Battery light on the Dash board (http://www.bimmerfest.com/forums/showthread.php?t=657433)

H2O 11-11-2012 12:36 AM

Battery light on the Dash board
 
Good Morning All,

i don't know if someone can help :confused:, i have 528i/1998 BMW and whenever i turn on the car in the morning the battery sign on the dash board keep turn on and off, sometimes fast and sometimes 4 to 5 second between each time.

take it easy on me, i am a rookie in BMW

thanks

QSilver7 11-11-2012 04:10 AM

According to the owners manual...I'd look into the alternator charging system first...that light illuminates when the battery is the VICTIM and is not being recharged...thus eventually killing it:


H2O 11-11-2012 06:05 AM

Hey QSilver7
many thanks for your reply, i will check it and keep you posted
regards.

H2O 11-14-2012 07:11 AM

Hey,
i tried the test number 09 for the battery and it showed it 12v, it should be 14 right ?
in this case the problem is in alternator charging system and it is not charging correctly right ?

Flybot 11-14-2012 08:09 AM

At idle you should have over 12 volts. Normally about 13V. When you rev it to around 2000 rpm you should gt at least 13.5V. It should never be less than 12V. Also, check it with the headlights on, and seat heat and/or rear defroster. It should carry a heavy load and still be well above 12V.


.

H2O 11-14-2012 08:32 AM

appreciate the info, i will try and do it and will keep u posted!
another question:
if i have some issue with the oxygen sensor and it is not working properly should the check engine sign on the dashboard be on or no.

QSilver7 11-14-2012 01:25 PM

Eventually yes. It takes several reading of the sensors registering a fault before the light illuminates. If you have a code reader...may see that a fault has occured, but the light hasn't come on yet. Again, this is because the sensor hasn't registered the correct number of faults yet:

(see the 2nd paragraph in the 3rd bullet)

http://www.bimmerboard.com/members/q...ne%20Light.jpg

Not all countries have the same OBD II mandates...nor did they occur at the same time for all countries that do:


H2O 11-16-2012 06:29 AM

Qsilver7
i really appreciate your help but can you please summarize what you sent :D
the issue is that when i placed my car on my friend scanner it showed an error code 76 which is the oxygen sensor but the check engine since is not on, i thought that the engine light is not working but i tried test number 02 and it showed me that the light is working

microswitch 11-16-2012 09:17 AM

I had exactly the same problem as you, an intermittent Battery Warning light.

I bet you my farm it has ALTERNATOR written all over. I just changed mine this Monday.

Do not worry about anything else. Take the alternator out ( 1 hour work) take it to a auto part have it tested ( guaranteed 99% faulty) and replace it. After the electrical system work as it should again, then check the other warning or codes you may have.

QSilver7 11-16-2012 09:56 AM

Quote:

Originally Posted by H2O (Post 7198112)
Qsilver7...can you please summarize what you sent :D

... when i placed my car on my friend scanner it showed an error code 76 which is the oxygen sensor but the check engine since is not on, i thought that the engine light is not working but i tried test number 02 and it showed me that the light is working

The CEL/SES light only illuminates when a sensor registers or senses a fault TWICE (or 2 times or more). If you plug in a scanner and see a code listed...but the light in the instrument cluster hasn't illuminated...it means that the sensor only experienced the fault once. And... if you add to the scenario like another over-arching issue such as a failing alternator/battery/charging system...the sensor that registered the fault could be a false reading (especially if it only occurred once) due to low voltage from the cars electrical system.

If a problem is detected and then re-detected during a later drive cycle more than one time, the OBD II system must also illuminate the Check Engine Light (Service Engine Soon light) in the instrument cluster to alert the driver that a malfunction has occurred.


In your case...before throwing money at a new 02 sensor...determine if the issue isn't a sensor throwing a false code due to low voltage etc. Again, you only knew about the 02 code by hooking up a scanner and seeing that a sensor had registered a code. Plus we can determine that "the fault" only occurred once since the CEL/SES light never illuminated. Then you add the fact that you were also experiencing an electrical issue (which could be the real culprit)...perhaps causing a false code from the OBD II system.

H2O 11-16-2012 11:36 AM

microswitch and QSilver7, i really appreciate your help and assistant about this, lets see what will happen! :$
keep you posted any way

doru 11-16-2012 12:02 PM

Quote:

Originally Posted by microswitch (Post 7198392)
I had exactly the same problem as you, an intermittent Battery Warning light.

I bet you my farm it has ALTERNATOR written all over. I just changed mine this Monday.

Do not worry about anything else. Take the alternator out ( 1 hour work) take it to a auto part have it tested ( guaranteed 99% faulty) and replace it. After the electrical system work as it should again, then check the other warning or codes you may have.

Before throwing the alt out, I would pull the brush/diode combo out and check it. This part if it's a Bosch alternator is around 40 bux. That's what I did on my car. The bearings were still good. if they start to fail, I will change tose out too. I have the replacements. Not difficult to do at all, and cheaper than a reman part. Reman parts can come with weak bearings, and a year later, the alt will fail and might take the belt with it as well.

0.02

H2O 11-20-2012 11:12 PM

Quote:

Originally Posted by Flybot (Post 7194208)
At idle you should have over 12 volts. Normally about 13V. When you rev it to around 2000 rpm you should gt at least 13.5V. It should never be less than 12V. Also, check it with the headlights on, and seat heat and/or rear defroster. It should carry a heavy load and still be well above 12V.


.

Hey there,
Hope your fine
i used your advise, i turned on the lights, seat heat and rear defroster and i enter test number 09 and it showed me a range btw 13.5 and 14.3, but the battery light on the dash board turned on maybe once or twice after that, then nothing.
what do you think ? should i worry :D
thankss

poolman 11-21-2012 04:03 AM

Go with Doru's advice--the voltage reg and brushes are built together in one unit--with a mirror and a flashlight you can remove the part from the alt without taking the alt off of the car--happened to mine just this way about 60k miles ago and all is well still with 240k miles on the car as of now. If you still having problems with 02 sensor--before replacing the sensor--check for vacuum leaks--there are many places that unmetered air can enter the engine and cause a code that reflects 02 problems concerning fuel metering

Flybot 11-21-2012 05:22 AM

Check the alternator belt to make sure it is not worn, or has oil on it, and is tight enough not to slip. If it looks ok, then I would go with poolman and suspect the regulator is bad. Either replace the alternator with a Bosch remanufactured or try just the regulator.

bluebee 11-21-2012 08:53 AM

I found this for you by typing /battery F3 in the bestlinks:
- DIY how to test a BMW E39 battery & alternator

H2O 11-21-2012 08:35 PM

Flybot, Bluebee and all, i really appreciate your help.
this forum has saved me a lot of money and time.


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