I am trying to get a light in a gauge in my car to become dimmer. How do I go about doing so? I want to keep the voltage at 12 volts but I want to lower the amperage by half. Would I have to by a 2ohm 72watt resistor in order to do this? Also I trying to find some sort of learning kit that is inexpensive that I may get in order to further learn how electronics work. Any suggestions on a good site, kit, or perhaps even a good book?