5 pin , 4 wire Dell Pc Fan

I have salvaged a PC fan from an old Dell Dimension E310. I was wondering what the color code was (except for + and -, obviously black and red) :slight_smile:

One is tach output and the other is speed select.

thank you :slight_smile: does the speed input use PWM?

Hi, try this site for a great explanation

it talks about the pwm issues, the speed input you refer to can be cut off to make a working 3 pin fan, it then leaves the gate of the fet floating, ie should turn on.


There is an Intel specification for PWM-controllable PC fans at Motherboard Form Factors and I have successfully controlled one of these from an Arduino. However, I think Dell fans work to a different specification, which I've never seen published.

Okay i used the example sketch AnalogInOutSerial, but the fan stayed at full blast =(