Originally Posted by
RcrMg
This is what I was originally thinking but I thought that the receiver always puts voltage out in each receiver slot on the + and - pins, and with only a two wire fan there is no signal to switch it on and off without some controller.
That's correct, the +/- pins on the receiver are all wired together so every set is getting whatever voltage is being used to run the receiver. The signal pin is PWM - pulse wave modulation, which won't work as a simple switch. You need an external device like the one above or these I found on Amazon: