It will tell you which terminals are common, which are normally open, which. Web it looks like you can control the led of this switch separately from the actual switching. Web if the switch should happen to be connected directly to the lamp, so that it also switches 12v (it may explain that third pin), you'll have to use a resistor divider to. Web wiring diagrams are especially helpful when it comes to wiring 12v lights, as they provide a detailed illustration of how to connect the different wires in order to. Web normal alkaline batteries have a voltage of 1.5v, and 8 in series will provide the 12v these switches need for the led.
