Or another easy way in testing, put your LED and the original bulb in parallel. The bulb loads the circuit so there is then power, and then the LED would also light. Just proves that the resistor would work.
Also, if you just try to test the output socket with a meter- for the same reasons the LED doesn't light, your high impedance volt meter might not register voltage on the output leading you to a false conclusion the board is bad or not outputing.
Wired the lights in parallel and the LED lights up for a second when power is applied then goes out so I'm getting somewhere.