2003 X5 battery drain

after several weeks of trying to solve the problem about my battery draining just after two days of non use, i still cannot find what causing my battery to drain if i dont use my x5 within two days. After reading here the same issue by most x5 users, I had the FSU replaced, i did not use my x5 for this weekend, I tried to start it, it started but just after a few seconds, lights on the dash start flickering and slowly my engine died. I tried starting it back again but not even a clicking sound, i jump started it and luckily it run and never died down again. Wondering now if there's just another problem causing my battery to drain or the FSU was defective. By the way, when my mechanic put the replacement part, he told me to start and keep the engine running, when i finally turn it off, he tried to put it back but the new FSU is just way too hot, is this normal or he has to put it back before starting the engine? Im afraid now that if it gets too hot inside, it might cause fire or something. Please help!!!!

Any non-OEM electrical equipment? I have read of people using Ipod docks or phone chargers, who leave them on, having all sorts of discharge problems. The item may not consume a lot of power but if it is more than around 38mA then the modules in the X5 never enter sleep mode and pull the battery down in a hurry.
If you have a look at the "FSU" you'll see it is pretty much all heatsink. (The prongs.) Given the amount of surface area they present I would expect it to get on the hot side at times.
I take it you have already had the battery/charging circuit checked?
GL.

Hi Zulu 95, i really appreciate the input, i tried checking the battery circuits and like i mentioned, i changed the battery and alternator and recently the FSU. Now that you mentioned it, there was a line for ipod etc. that has been laying beside my shifter , i'm going to mention that to my mechanic, maybe I should just have it taken out completely just for the sake for eliminating one probable problem. I will keep you posted and again, thank you for your help.

Hi again Zulu 95. I forgot to mention, i took out the temperature control unit last night after parking the car. As usual , the small fan keeps on spinning after i turned the engine off. I did this because my mechanic said that this is the one that is draining my battery. One thing though is the blower ( I think is the heater) keeps on running although the whole unit is already out, is this normal? I can feel too that there is too much heat under the steering column whenever i drive the car without the temperature control engaged.

Thought this might give you another idea. thanks again.

rudy

If the blower keeps on running then you need to check the FSU. When you replaced it did you use an after-market ebay special or the OEM part? The "cheapo" just like OEM FSU replacements you get usually fail very quickly. If I remember correctly on xoutpost one owner did the job himself and it failed right away or within a few hours.
What small fan? there are small fans behind the mini grills on the HVAC head unit to feed the cabin temperature sensors for each side. Do you mean these? They should be off when the vehicle is off.
The ipod cable should be treated as suspect if it has some sort of charging circuit.