Battery Issue

[cuban_bmwx5]

hey guys
so i have a issue with my X5 for some reason i have to boost it pretty much all the time i boost it on saturday then sunday i start it up fine then monday dead..
i got a new battery installed from bmw dealer and they did a test on the alternator they said it was fine so this issue got me stumped.. now what i want to know is a friend on mine has a e39 and he said he had the same issue some one told him it was the blower regulator he fixed it and now its fine. could that be my issue as well? just wanted to see if anyone else has dealt with this same issue.
thanks hope some one can help me out
(oh and the blower regulator is number 2 on the pic)

[Crowz]

There are soooo many things in an e53 that can kill the battery. Mine was the Bluetooth module (tcu). Unplugging it is a simple test to see if that's the issue on it but again there are tons of possibilities.

But if you have the Bluetooth unit its a good a place as any to start. Search the forum for what to unplug there are post with pictures of it.

[Perrier]

Put a multimeter on the battery and check its load while removing fuses out of the box.
Remove 1 fuse at a time and check for voltage variation. It will lead you to the culprit

[Fifty150hs]

Originally Posted by Crowz

There are soooo many things in an e53 that can kill the battery. Mine was the Bluetooth module (tcu). Unplugging it is a simple test to see if that's the issue on it but again there are tons of possibilities.

But if you have the Bluetooth unit its a good a place as any to start. Search the forum for what to unplug there are post with pictures of it.

The three most common causes of parasitic drain are the TCU, The Nav (if you have it) and the FSR. Pull one fuse at a time and you will find the cause. My money is on the TCU (fuse 74) as that seems to be the most common cause. Pull the fuse and see if that solves your problem.

[cuban_bmwx5]

Originally Posted by Crowz

There are soooo many things in an e53 that can kill the battery. Mine was the Bluetooth module (tcu). Unplugging it is a simple test to see if that's the issue on it but again there are tons of possibilities.

But if you have the Bluetooth unit its a good a place as any to start. Search the forum for what to unplug there are post with pictures of it.

well i have aftermarket unit that has bluetooth my stock i dont think it came wit the bluetooth

[Fifty150hs]

Originally Posted by cuban_bmwx5

well i have aftermarket unit that has bluetooth my stock i dont think it came wit the bluetooth

Check and make sue you don't.

[cuban_bmwx5]

Originally Posted by Crowz

There are soooo many things in an e53 that can kill the battery. Mine was the Bluetooth module (tcu). Unplugging it is a simple test to see if that's the issue on it but again there are tons of possibilities.

But if you have the Bluetooth unit its a good a place as any to start. Search the forum for what to unplug there are post with pictures of it.

well i have aftermarket unit that has bluetooth my stock i dont think it came wit the bluetooth

[cuban_bmwx5]

Originally Posted by Fifty150hs

Check and make sue you don't.

i am gonna have to check the original deck and see if it has bluetooth

[cuban_bmwx5]

Originally Posted by Fifty150hs

The three most common causes of parasitic drain are the TCU, The Nav (if you have it) and the FSR. Pull one fuse at a time and you will find the cause. My money is on the TCU (fuse 74) as that seems to be the most common cause. Pull the fuse and see if that solves your problem.

my x5 did not come with nav stock .. my aftermarket unit does have one tho

[Crowz]

Originally Posted by cuban_bmwx5

my x5 did not come with nav stock .. my aftermarket unit does have one tho

You can have Bluetooth without nav. Overboost's X5 is like that.