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Steve
Steve, BMW Expert
Category: BMW
Satisfied Customers: 24180
Experience:  BMW Expert
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My friend has BMW 5.25d 2005 his problem is battery drain he

Resolved Question:

My friend has BMW 5.25d 2005 his problem is battery drain he replaced the battery still the same problem could you help please
Submitted: 2 years ago.
Category: BMW
Expert:  Steve replied 2 years ago.
What has been checked so far?
Customer: replied 2 years ago.
My friend is away for one week .i cannot give anymore info until he returns. .is that ok Steve
Expert:  Steve replied 2 years ago.

I can provide an answer now if you like, I just try to determine what has been tried so I give the most relevant information. it is up to you.

Customer: replied 2 years ago.
Steve i can give you more info when my friend returns in 7 days time .if that is ok with you .regards norman
Expert:  Steve replied 2 years ago.

sure, please return to this post then.

do not open a new thread or you may end up being charged twice.

Customer: replied 2 years ago.
Steve I am sorry I am late in returning more intimation to you .my friend said the garage said the problem might be to do with the radiator they were not shaw .hope to hear from you soon regards Norman
Expert:  Steve replied 2 years ago.

I will provide an honest answer. I trust this will be appreciated. Please remember that a low rating PUNISHES me for being honest and that I receive nothing for my time until a positive rating is clicked.

What you are experiencing is called parasitic draw. This is actually somewhat common.

There is some component on your vehicle that is draining power overnight while the car is supposed to be off.

If you have any kind of aftermarket equipment installed (GPS, ipod dock, etc), this is the first suspect.

If there is no aftermarket equipment installed, the blower motor resistor is by far the most likely culprit. Also, the electric engine fan is also somewhat common.

Beyond these items though, it could be ANY component on the car.

In order to determine the cause of this, you will need to unhook the negative battery cable and hook up an amp meter and measure draw after the car is locked and has sat untouched for 20min (this is when it is supposed to be in "sleep mode"). If there is more than about 50ma of draw at this point, you will need to pull fuses one by one until the draw stops. Whichever fuse stops the draw is the problem circuit.

If you are not familiar with using this equipment or performing this type of test, you should have it carried out professionally.

BMW dealers also have special equipment they can use to help identify the cause of this, so this is a second option, besides the above test.

As I mentioned, the blower resistor or electric engine fan are the first items to start by checking. So simply pulling these fuses for starters and seeing if the draw persists should be an easy first step prior to a full on draw test with an amp meter or dealer power diagnosis.

Please let me know if you have further questions. Please do not forget to click a positive rating as this is the only way I receive credit for my answer, thank you. Best wishes with your vehicle.

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