I'm having this same problem on a 99 328i manual car. The fan keeps running when the car is shut off and it will just keep running until it kills the battery. This happened today -I could hear the fan running when I shut the car off and didn't think much about it.
When I went out to the car in the evening is was totally dead. When I hooked up the jumpers the first thing that happened was the fan turned on again! I started it up and ran it for a while and when I shut it off the fan was still running. So I disconnected the connection right at the top of the radiator and it shut off. I noticed that the third pin of the connector on the fan side seemed like it was broken off???
So I need to replace the fan? THe module that is in there has a temp sensor and relay in it?
I noticed there are fans as low as $111 on ebay.
Oh and this fan is listed as the AC fan. Do you need this for daily driving without the AC on?
What about that coolant temp sensor, could that make the fan constantly run?
Last edited by xdave; 08-03-2011 at 04:00 AM.