Most likely the resistors are the current limiter for the leds. I'm not sure what voltage is supplied, but most likely 5v. So depending on what the voltage drop across the diode is and how much current you want flowing through them you can find the resistor size from Ohm's law.

Hugo, what are you driving the leds with to be able to dim them? Are you using pulse width modulation or an analog output?


-Waiting to replace the hole in my truck with a Mark2