Battery Drain

[aliris]

FSR - final stage resistor
hedgehog - look at the item and you will know why it's called that name
blower regulator -blower regulator

they all referring to the same thing..which control the speed of aircon blower motor..

symptoms when this failed
1. blower on one speed only or
2. blower not functioning at all
3. blower turn on by itself even when the key is out of ignition (which will drain your battery overnight)

http://wwww.bimmerfest.com/forums/showthread.php?t=209002

the picture of the fsr..

If it is the case, I recommend you to get a genuine one as I had bad experience with the aftermarket unit (blower makes humming sound )

 

[jarance]

aliris, I think you are most probably right.

looking at the circuit, the blower is control by F76.

I think I know why the current did not fall when "all" the fuses were removed. This is because the mechanic
did not know where fuse F76 is and did not remove it. For E39, there are 2 special fuse under the glove compartment.
It is 3 times bigger in physical size than the normal fuse.

btw, you did not need to remove the glove compartment to access it. Just remove the cover under
the glove compartment by sliding it toward you. the fuse is hiding there. (use a torch)

 

[joeyc]

If you've not done any mod to your car prior to this, the most commonest source of power drain overnight is the FSR@hedgehog@blower regulator. If this is the case, when you lock the car , the blower will run on its own until the battery is flat without you knowing it.

Rule that out already. No problem with that.

 

[joeyc]

aliris, I think you are most probably right.

looking at the circuit, the blower is control by F76.

I think I know why the current did not fall when "all" the fuses were removed. This is because the mechanic
did not know where fuse F76 is and did not remove it. For E39, there are 2 special fuse under the glove compartment.
It is 3 times bigger in physical size than the normal fuse.

btw, you did not need to remove the glove compartment to access it. Just remove the cover under
the glove compartment by sliding it toward you. the fuse is hiding there. (use a torch)

Jarance thanks for the valuable info.