Could anyone suggest a reason why the auxiliary fan in my 2003 X5 keeps running even after the engine and ignition are shut off? I presume it's the auxiliary fan but don't know for sure. The fan noise is emanating from the area where the cabin filter is installed under the hood near the firewall. Is it supposed to run all the time?
Tonight the fan sounds as if it's running at a constant speed. On other occasions (last night, for instance) it sounded as if the speed varied. This observation is based on the pitch of the fan sound. It appears to keep running for hours after the engine and ignition are shut off. The car has been off about 3-4 hours tonight and the fan is still running.
There doesn't appear to be any way to get it to shut off. Last night I started the engine, turned off all interior fans, then shut the engine off. The fan noise continued for several minutes (variable pitch noted) then stopped. I tried the same thing this evening with no luck.
A Peake Research scan tool reported no codes.
The vehicle is out of warranty, so any help would be appreciated.
Thanks in advance!
~ Dave