Overheating Problem DME 2EFE fan shorted

Earlier this week my 2005 645 overheated. When I raised the hood, I saw coolant spraying from the recirculation line across the top of the radiator. The local dealer had to order the line. Changed the line, and the engine continued to overheat. I then found a crack in the coolant tank. I have changed the tank, still overheating. I have bled the system as good as I can.

I used DIS to check for codes. The DME showed a fault with the radiator fan. It says that it has a short circuit to ground. I can clear the code, & the fan will run until the ignition is turned off. Today I replaced the sensor on top of the lower line coming from the radiator. The engine is still overheating. I can drive the car with the heater on high, but when the AC turns on it starts to overheat.

It's hard to believe that the fan is defective. It does have an internal circuit that controls the speed, based on temp. Does anyone have any suggestions, before I have to take it to the local dealer. The fan will cost around 600.00. I don't mind spending the money if it fixes the problem, but I suspect another sensor might be the culprit! I have read all post on overheating, but none have helped.

Please help!

Thanks in advance
Edit/Delete Message

I'd invest in dual Electric Fans. Car will never run hot again and will cool beyond the OEM solution. INDY should be able to knock this out at the same or less prices than the dealer.

had the same problem last yr change the fan b4 u mess up your engine.. if u look at my previous post you will see the misery i went thru with the cooling system.

Thanks for the replies. I took it to the BMW dealer today, and the mechanic confirmed my diagnosis. I am going to install an aftermarket fan from O'Reilly's. For 525 dollars it has a lifetime warranty. The BMW fan was 616.00 , with only a 2 year warranty. The fan failure seems to be a common problem.