the wire broke on the fan, I tried to fix it but couldn't
How did you fix it?
If you were just trying to repair without replacing the wire maybe the wire you are trying to fix is already snapped from the inside so you should replace it with new one.
On 4 wire fun I connect red and black, fan is working in very low speed
I think the reason why it runs so slow is because the wire can't handle more power that came from the PSU that is why I suggested in my previous post that replace it with thicker wire gauges.
If you replace it with thin wire the fan will get less current from the PSU and it only runs half or less than the original wire.
