The OEM fan fuses are a 40 amp and 50 amp based on the diagram I have, so I would be surprised if they only pull 8 amps. Can't remember an OEM fan that pulls so little. I bet the OEM wiring is 10 gage or bigger, too.
There is a 10 amp fuse for the control side of the relays, maybe that is what you are referring to?
ADHD wins again.. my head talks about to many things at once. Sometimes, I'm typing wayyy slower than I'm thinking and my brain has already moved on to something else haha