The fan sounds perfect when its running though very quiet and seems to work as it should. if a bearing was gone it would be very noisy. Seems to be more of an intermittent electrical fault. Probably have to strip out the fan and take a look
I did mine recently. Was ok too. Then became intermittent and only worked only round sharp bends! Swapped out and all is fine again. I agree with correct diagnosis too. You should be able to strip the cowling back to get a multimeter on it with not too much hassle.
This is my BMW. There are many like it, but this one is mine. My BMW is my best friend. It is my life. I must master it as I must master my life. My BMW, without me, is useless. Without my BMW, I am useless. I must drive my BMW true......