2003 BMW X5 fan runs after engine is off, drains battery

How would it be a blown fuse--- I ask?

If a fuse was blown-- how would the fan have
a complete circuit-- in order to run at all?

Have to diagnose the fan control circuit, to
find a problem

I am having the same problem with my 2002 X5. There is a motor or fan running behind the AC control panel on the dash and if I pull fuse 48 it stops and the battery doesn't drain. Still looking for the cause and solution so that I don't have to keep pulling and installin fuse 48. BMW garage suggested that it was the Final Stage Blower Resistor. I replaced this and no change. I hope someone has an answer that will help us both.

Is the battery and the battery connection in good conditions? Try to charge the battery overnight with a battery charger. If then it starts your engine, the battery may be ok.
I recently had an issue with my car that the connection to the battery was corroded that was not visible just by looking at the battery. The connection had to be cleaned and solved the issue.
If the battery and generator in your vehicle is ok, then it must be a short circuit in the car that drains the battery. Locating that may require shop visit.

If you do not run even one level of performance as the needed engine control unit, check fuses! If they are okay, the fan is defective! is a frequent defect no only X5 E53 series

You need to check for any lighting left on overnight if not try to fully recharge your battery and perform a load test on it to see if it will hold the charge if so possible drainage off of interior lighting switches or alarm possible

its the final stage resistor in the air con needs replacing

First check the battery terminals are clean and firmly attached- if terminals are ok the battery may be either discharged or faulty.
Get the engine started by jumping from another battery- then check battery running terminal voltage is approx 14.5 volts with load such as headlights or heater fan on.
If voltage ok and battery still doesn't hold charge, the battery is probably faulty - replacement required.

hello theringbar, I would recommend checking the a/c blower resistor. it is an electronic final stage and can kill the battery overnight. the final stage is located on the passenger side at the back of the a/c heater box.

Connect your old battery with another battery from another car (WHILE KEEPING ALL CABLES CONNECTED ON BOTH CARS) just user a bridge cable otherwise you'll need. a code to reactivate your BMW again. Try now to start your BMW engine. Now go to the nearest battery dealer to change the battery WHILE KEEPING YOUR ENGINE ON, otherwise you'll need a code to activate your BMW again :)

Good Luck!

you will need to replace the heater resistor to cure this fault