I barely replace the power steering pump like 3 weeks ago, and drive it today without problems but then when i turned on in the night the power steering pump doesnt work no more, i dont know if its the pump again or a fuse because i change the PS fan and the fan is working perfectly, what should i do?, how could i know if its just the fuse?

thanks

Easy, change the fuse, if it then works, it was the fuse.
If it still doesnt work check theres power there using a multimeter.