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Discussion Starter · #1 ·
I have a 2005 325Ci Sport.
I went away for a few days and came back to a car with a dead flat battery.
Its not the battery because it is only a few months old.

I tested the car with an Ammeter and found that with the key off and all interior lights off (boot included), there is a current draw of ~2.24Amps.

I pulled fuses 1 by 1 and found that ~0.2A was coming from the Instrument Cluster, Sun Roof and Thief Proofing System. I also found that there was 2A coming from circuit 41 (Navigation/Audio), I found the problem circuit...

This is where the problem gets the better of me...
I started disconnecting the various devices in circuit 41, e.g. amplifier, GPS DVD player, Audio Head Unit, and found Amperage drops when each device was disconnected. That means there is not one device causing the entire 2A draw, its as if all the devices are on and working. (the key is off)

Am I right in thinking that circuit 41 could be getting power even with the key off, and that the Current Draw is just the devices in the circuit being left turned on?

If so, from reading the circuit diagram (and I'm not an electrician) it seams that the only "switch" is the circuit is the ignition.

So my question is; do I need to look at the ignition, or is there some other type of switch or solenoid I don't know about, or have a totally overlooked another issue that could cause this to happen? (Or do I bite the bullet and take it to an auto electrician or BMW?)

My apologies for such a long winded question. I can post the exact figures from the multimeter if needed.

If somebody can help it would be much appreciated. :)
 

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Discussion Starter · #3 ·
When I first connect the battery (no key) I do here the fan in the amplifier for a couple of seconds, as well as the GPS DVD spool up for a few seconds too.
I thought this was normal, maybe its not? Would this be sounds your talking about?
Also, the LCD screen turns off, but there is still power to the unit, I checked with the multimeter.

Ignition switch?
 

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Sounds like the culprit. Also, check to see if there's a relay between the inhibition switch and the power to the electronics causing the problem. I don't believe that there is one but I'd check anyway.


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Discussion Starter · #5 ·
I've checked, but there isn't one that I could find, thanks for your help!


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