Thank you all for your replies!

I'll test it to figure it out.

FYI - There is no red and black - they are all black with the same white printed stripe.

FigJam- I am building this and bought the fan you recommended. The fan comes with 4 wires attaching to a white clip; how do I determine which of these wires is positive and negative? I will be attaching it to a solar panel & battery set up. Thank you. Sorry if this has already been asked, but I coul...