Confused On PWM - High amp 2 wire fan

Hello,

I am trying to control this fan
http://derale.com/products/fluid-coolers/universal/remote-mount2013-10-28-09-53-271073910258/15875-detail

based on the temperature of the fluid. I would like to vary the rpm speed based on the need to try and get the temperature as close to 190 as possible.

I wrote the manufacture and they said this
'all fans are PWM compatible as the voltage is just being pulsed to modify the speed of it.'

usually I am use to a 3rd wire for the pwm pulse.

My question is, how can I control this 2 wire 12v fan using 'pwm'
(picture of the connector https://www.jegs.com/images/photos/200/259/259-15875_4.jpg )

Thanks in advance.

You need a MOSFET or motor controller which can handle the peak amps required by the fan. The web page says 8.7A but the starting current could be over 30A. Maybe buy a Monster Moto shield from Sparkfun and wire both channels in parallel. (One is probably sufficient.)

thank you, i will look into it!