Heaven help me - I've just bought a delta kit :-)

[mjf55]

I added the part cooling fan and your fan duct work. I did reverse the wiring to try to figure this out, but the fan would not start at all, neither the S0 or S255 would start it. Tried another fan ( blower type this time ) and same behavior. A HE3D facebook member suggest just to reflash it. I am not convinced, but will give it a try.

EDIT:
So I reflashed, and no difference. Will open a service ticket.