My mistake, 8amp. My recall my not be, but all of the fuses are correct
Basically, that circuit appears to be fine or potentially on the brink using all components other than the aux fan/relay.
So either the fan relay takes it right over 8amps, or it’s near 8 amps because of some issue elsewhere in the system.
Is it possible to test the amount of current running through the 12 fuse before running the fan, and potentially after it blows?