Replace fan control module?

[wfuerte328i]

I recently slapped a new ac compressor in my 00 328i, and everything was working fine. a few weeks ago, the ac stopped working right and now my cars overheating. the cooling fan isnt kicking in, so i took it to a mechanic and he told me pretty assuredly that i need to replace the fan control module. is this a common problem with this model, or might it be something else?

[wfuerte328i]

I called around only to find out that my "mechanic" doesnt know what the hell he's talking about. I felt like an ass for calling around for a non existent part. i called the bmw dealer and a technician said it sounds to him like i need to replace the coolant temperature sensor, i found some for pretty cheap so i think ill do that, but can anybody tell me where the heck its located at? thanks

[wfuerte328i]

nevermind where its at, i found the part. but is there any way i can test it some how to find out if it is the problem or not before i buy a new one?