if you whant to change the lamp on your panel, you realy need to know the voltage on the lamp(14v max normaly) there is the equation E=RI (E=Voltage, R=Resistance and I=current)a regular LED spec, 2.4v at .02a (2.4v / .02a = 120 ohms)the max voltage on your lamp (14v) - led voltage (2.4v) = voltage ...