Properly connect CPU fan

[Adenitz]

Hello,

I need to replace CPU fan and the replacement part has one free wire that is not connected to the connector. At first I thought that it has broken from the connector, but this is not the case, since it can be found on the pictures of brand new fan on ebay.

Is this normal wire or it has some special purpose in terms of sensing the temperature or something?
It seems that this wire is just soldered on the metal of the heatsink.

[Adenitz]

Re: Properly connect CPU fan

Update:
It appears to be a sensor wire. So the question is how to properly connect it to the frame without destroying it? I guess using solder iron would destroy it.
I have found an explanation of this additional wire here on this yt video.