Dual fans on a Dual Extruder?

So i’ve been getting my dual extruder all set up (blew a fuse the other day so I haven’t actually been able to test it, logic works but motors are inactive right now). I went so far as to build another extruder snake cable so everything is all nice and organized, BUT: I can’t figure out how to use the fan connector on the second extruder cable. Or if that’s even possible with the current firmware. It looks like the hardware is all set up for it, but I can’t find any option in the LCD screen, nor in my control software… or in the firmware. Is the second fan controller meant to work a different way? It’d be nice to be able to do dual-color PLA prints or the like…