The
led lights up when the turbine starts to spin fast, that means it's
charging, if the led starts blinking that means it's shorted, i imagine you have it connected without an external
regulator?
What you can do is connect it directly to the
battery bypassing the kill switch and any external
regulator or dc meter, with the positive and negative disconnected it would have to spin fast without resistance, if you put the positive and negative together it shorts and stops, try it directly on the
battery to see what happens, if it stops after a while with the led blinking, it may be that it has a fried diode, a bad connection right where the ground + - are connected to the turbine, or a bad battery.
You can also try to remove the blades and try by hand to spin the shaft, some resistance with the turbine wired to the battery is normal, to much and its shorted.