Parasitic battery drain
 

I seem to have a parasitic battery drain on my 52 e53 3.0d. This was present when I bought it and a new battery cured the problem for about 3 weeks. Alternator is charging fine at .between 13.5-14.0v and a diagnostic check suggested maybe interior light module noted by the garage bulb checking drain. However. It appears that it may be linked to the stereo system. If I pull the first 10amp fuse in the boot which disables the radio function I have no issue starting her up the next day. This is day 2 of trying this method. Can any inform me what other function this particular fuse links to? And has anyone else had a similar problem. Driving me nuts !!

Your auxiliary fan resistor is shot, when the car is off You should hear it running in the dash...........

Final stage resistor? Is this linked to the same fuse or does it have another?

I've suffered fsr problems in e46s and am aware of the symptoms. The fan in the x5 seems fine. No over run or rough running at any speed on the fan settings. Air con has recently given up the ghost but I'm assuming this needs recharging as I heard the hiss noise prior to it going. I'm more convinced that it's linked somehow to the radio/amp. Everything works fine but of the fuse is left in that's when I get problems. Ok it's early to assume this but on the days I've not removed the fuse this week the car started ok. Does the radio or amp have a permanent live? I can't actually see the amp (assuming it's in the boot area) but someone also said of its missing the car won't slee due to searching for this component.

drain
 

I chased a similar issue for two years. one day the alternator died. After I replaced it, the drain was no longer present

Would be nice if it was that simple but alternators showing as fine in voltage check. Still think it's linked to the radio in some way

I am suffering exactly the same issue....the 10amp fuse you are on about should be a 30amp though. Mine drains over night if the fuse is left in, I've had it to an auto electrician twice now...the first time I was told it was the radio module in the boot under the spare wheel so I had it repaired but still no joy...the second time he found that the purple/white wire in the multi plug was still pulling 8v after the ignition is off.. when he's tried to find where this goes to all he's been able to find out is that it goes to terminal 15 (where ever the hell that is...lol)...he says he's struggling to find a good wiring diagram for the car....so I'm now trying to find a solution myself have you had anymore luck yourself in finding a cure.

Well at least we have the same problem. I'm aware of the 30amp and a little research suggested same as you have said. Radio module. I'm yet to get it fixed so if you beat me to it let me know. My auto electrician said interior light module but clearly was wrong. The module lives under the air suspension compressor? I've yet to get to it. I noticed that when the fuse is left in the car doesn't sleep so I'm guessing this has to be the problem but as to exactly what I'm unsure. I'll keep you updated if I get to the bottom of this