There are only two wires: red and black - there is no speed control wire.
If you want to see the components of the ASUS EN6600 GT Video Graphics card heatsink / fan, it is easy to remove the various parts. It may be that it will work better with just a clean.
First turn the fan over and undo the four small philips screws (marked in red on the picture below). This will allow the clear plastic cover to be removed..
Turning the fan over, the label on the back show it to be an:
“Everflow DC Fan & DC Motor
DC 12V 0.15AMP
Made in China”
made by the Everflow Technology Corp. which was founded in 1976 and has a production plant in Dong Guan City, Guang Dong Province, China.
To remove the fan undo the three small philips screws (marked in red on the picture below) under the fan blades
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