Originally Posted by vinuneuro

The aux fan was part of a massive recall for 01 BMW's. I would look into it.

2001 BMW X5 Recall ID from NHTSA: 01V206000 Auto Recall Date: 20010621
Vehicle Component: ENGINE AND ENGINE COOLING:COOLING SYSTEM:FAN
Estimated Vehicles Affected: 76469
2001 BMW X5 Defect Summary:
VEHICLE DESCRIPTION: PASSENGER VEHICLES. THE ENGINE AUXILIARY/COOLING FAN OPERATION, INCLUDING VARIABLE SPEED, IS ELECTRONICALLY CONTROLLED. FAILURE OF THE FAN MOTOR CAN CAUSE THE ELECTRICAL CIRCUITRY OF THE FAN CONTROL UNIT TO OVERLOAD AND FAIL, CAUSING THE FAN TO STOP OPERATING.
Defect Consequence:
IF THIS WERE TO OCCUR, ENGINE OVERHEATING AND SUBSEQUENT ENGINE DAMAGE COULD RESULT. IN ADDITION, IT IS POSSIBLE FOR THE FAILURE OF THE ELECTRICAL CIRCUITRY TO CAUSE A FIRE IN THE FAN CONTROL UNIT LOCATED IN THE FRONT OF THE ENGINE COMPARTMENT.
Remedy:
DEALERS WILL REPLACE THE FAN. OWNER NOTIFICATION BEGAN SEPTEMBER 28, 2001. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT BMW AT 1-800-831-1117.
Notes: BAYERISCHE MOTOREN WERKE,