powered led generator works but with other power source with voltage divider at same volts don't
When your motor is generating the power, all of that power is going to feed the LED.  However, when you go to use the voltage divider, you are creating a draw on the voltage divider at the point that you are getting ~1.76 volts.  A much better configuration is to think of the LED as a resistor.  It takes voltage and drops amps.


If you put the LED in the place of the LED resistor, then you have limited the voltage to it and it should light brightly.  Additionally, if you look at the current flow through the 'resistor', you will see that it is ~1.5mA.  That amperage is not likely to be close to the max so you won't shouldn't blow out the led.