The blower final stage fan resistor is known to fail. Symptoms are the heater fan speed varies regardless of the setting, the fan will not turn off when the car is switched off, or the fan will not switch on at all.Google+
Car Problem Reports
BMW X5 Blower Final Stage Fan Resistor May Fail
BMW X5 Problem
Average Mileage: 87,382 mi (10,045 mi - 165,100 mi)
Visitor, 2002 BMW X5, 156,000 mi
after I leave my car overnight and morning the battery low
Visitor, 2000 BMW X5, 87,950 mi
Replaced this failed part in January 2011 when the fan would not turn off. It seems to have just failed again in June 2014 but this time the fan won't turn on. It has stopped blowing briefly and then started working again 3 times in the last month but I think it's finished this time.
Visitor, 2001 BMW X5, 87,000 mi
Dealer charged $250 for parts and labor. I wished I had came across BMW forum and can take care of it myself and save money :-(
Visitor, 2003 BMW X5, 85,000 mi
It's mostly a trickle fan that out of nowhere decides to blow on high speed. I've been told it's a resistor.
I am on my 2nd resistor in just over a year,and just again in November 2011!!!! I replaced my 1st one in July 2010 and last month October 2011. Are their parts becoming low quality????????
Visitor, 2003 BMW X5, 113,000 mi
ac or heat not blowing
Visitor, 2002 BMW X5, 10,045 mi
Took to mechanic said i needed a A/C final stage unit
Visitor, 2002 BMW X5, 54,000 mi
I bought this car at 54,000 miles and the max button on the heater does not work and has not since I bought the car. Now the entire heating system seems to be acting strangely with the blower only working occassionally.
Heater fan speed varies regardless of the setting, the fan will not turn off when the car is switched off, or the fan will not switch on at all. Asked BMW to address this issue when car was new, but they stated that could not fix it unless I brought it in when malfunction was taking place. Due to it happening off and on, it was impossible to time that just right.