I'm trying to plug my cpu cooler fan and two other 120mm fans which are rated for 0.25A using a splitter.
but I'm not sure about the amperage of this cooler fan?
Have you tried lifting the fan and checking the sticker beneath?
Another alternative could be a sata to fan adapter splitter. Or a sata powered small controller.
nvm a friend tested it for me using a multimeter
it's 0.09A max and rarely spikes at 0.1A
Then you'll be OK. Fan headers should handle well 3x0.3A fans
Was it at 100% fan speed