DC cooling fan question

[lo7100]

I need to buy a DC cooling fan but it ususally comes with a 3 pins connector. The problem is that I have a DC adapter but it has a 2 pin connector. How can I connect the 3 pins to 2 pins together??

thanks in advance

 

[Widdy]

3rd pin (usually white or yellow) is RPM sensor/Tachometric Signal. Won't be needed for your application.

 

[lo7100]

OK. I have a 12V fan with 0.11 A. I used a 12V 15W 1.2A transformer to run it but the fan won't move. Then I used my finger to turn the blade a bit then the fan moved very slowly. Any idea?