My PSU fan is working, but PSU isn’t outputting any power to it

[samn.a601]

My PSU fan isn’t spinning at all, I tested the fan by connecting it to a 12v power supply and it spins freely but when I turn the PC on the fan doesn’t spin. It seems as if the PSU is not outputting any power to the fan. Even when it gets hot it still doesn’t get turn on. The PSU is a Antec Earthwarts EA-380 80+. Also when I tested the PSU fan I did it while I was in the case and when I connected the positive to it the whole case acted as a negative power port, is that normal.

 

[Dark Lord of Tech]

Should be running , it's not one that has a thermal limit to reach before coming on.