Hello all ,So as the title states I have a constant battery drain that leave the car with a dead battery in 12 hrs if engine not started and run, It took me awhile to track down where my drain is occuring but I am getting close to excat Isolation of this parasitic drain, the drain started a couple months back and I did go through the entire fuse box takeing amprage reading on every fuse, but this led me to really nothing, There are so many fuses that do have a small amprage draw that it really leaves you in a state of guessing. so I delt with keeping a battery charger on my car for most of this winter , And yes before I ran all my test I did lock my car and let it go in to sleep mode / rest mode. and yes before any test were done I started with a brand new interstate battery.

So one day while thinking about my problem I remembered that at one point last year I had 2 issues arise electricaly , the fist was on two ocations my radio did not turn on and one of those times the screen did not open and or black screen with radio in use and on, the other issue happen more recently ,Witch was my bluetooth stoped pairing with my phone , and my system it self shows no evidence that I even have bluetooth on board, So the first thing I did was to disconnect the Telematic control unit located in the rear of the x3 , this had no effect and I still had the battery drain.


So the next thing I did was to remove all fuses that had any link with Navigation , bluetooth , radio CD and display Screen. Presto magic no more battery draw , So radio fuse 7 , then fuse 42 witch is navigation and display Screen, and I think CD portion of the radio but I am not sure when I pull the fuse the navigation does shutdown and the display screen does not work ,but unsure of the CD ,I only have symbols on my fuse card with no discription of what the fuse is powering. Fues 42 show a symbol of what looks like 3 cds stacked up. the next fuse pulled was fuse 9 witch show to be the display screen ,the next fuse pulled was 39 this is the phone fuse . the last fuse is fuse 41 but this fuse needs to stay in because the car will not start with out it.

So after pulling fuse 7,42,9,39 the problem of battery drain has stoped , now I started to isolate this drain I put fuse 9 back in and found that I still had no drain on the battery the next fuse I put back in was 42 and my battery drain problem reared it ugly head again with a dead battery the next day....

So as of now fuse 42 is the problem , I am goin to charge my battery with fuse 42 pulled ,then proceed with installing fuse 7 witch show links with radio,display screen and phone system, and see what happens there , and then the next day I will install the final fuse 39 witch show link with phone.


Would like to know your thought on after I get to the bottom of this Parasitic battery drain , Should I replace what ever component is faulty with OEM component or just replace everything with after market radio,nav,phone system thank you for taking time to read J