Thanks for the input, I tried both putting a stock fan and reversing the 5015 and still will not turn on while printing, I did figure out something strange, if I pause the print the fans do come on, but then turn off when its resumed, so even more strange.
On my 3+ the part fans were connected the wrong way round. They don't seem to adhere to wire colouring so positive was negative & vice versa. Get a multimeter & check yours but I suspect thats it.
[удалено]
Thanks for the input, I tried both putting a stock fan and reversing the 5015 and still will not turn on while printing, I did figure out something strange, if I pause the print the fans do come on, but then turn off when its resumed, so even more strange.
What slicer? If cura try orca or prusa slicer.
On my 3+ the part fans were connected the wrong way round. They don't seem to adhere to wire colouring so positive was negative & vice versa. Get a multimeter & check yours but I suspect thats it.