The version 2 of the f18 has a new BEC installed external and it's call UBEC.
The BEC plugs into chan 6 on receiver. The ubec draws power from the battery and it will provide power thru the port that's plugged into channe 6.

The ESC plugs directly into the channel 3 and the center red wire on that plug should be cut off. Let me know if you still need help.

John
Nitro Planes