What is your electronics setup?
What version of Marlin are you running?
Marlin has some options to control additional fans, but like Dust has already mentioned, not all electronics has the mosfets to be able to take advantage of those optional settings in Marlin.
What version of Marlin are you running?
Marlin has some options to control additional fans, but like Dust has already mentioned, not all electronics has the mosfets to be able to take advantage of those optional settings in Marlin.