Need help configuring extruder_fan & part_cooling_fan

Hello,

I am trying to configure marlin 1.1.8 working with my printer, but I am having problem working the extruder_fan and the part_cooling_fan.
Can anyone please help?

About the extruder_fan. I have set pin 8 in RAMBo board, which is the FAN0.

#define E0_AUTO_FAN_PIN 8

But it gives me the following:

SanityCheck.h:977: error: #error "You cannot set E0_AUTO_FAN_PIN equal to FAN_PIN."
#error "You cannot set E0_AUTO_FAN_PIN equal to FAN_PIN."

There must be a problem in the code, because in marlin 1.0.2 it was working fine.

And about the part_cooling_fan. Where do I change the pin? In which folder?

Thank you all.