A continuity tester is a device that tests the continuity, or, electrical "soundness" of a conductor (anything that conducts electricity). A simple one can be improvised by connecting a light bulb from a flashlight to a length of wire (do this by wrapping the bare end of the wire around the threaded part of the bulb, and taping it in place); the other end of the wire to a couple batteries (taped end to end, as if in a flashlight). At the other end of the batteries, attach another length of wire. (The ends of the wires need to be bare, by the way). Now, if you place the tip of the light bulb onto one of the "L2" terminals, and the loose end of the second wire onto the other, the light will glow to show that the terminals are interconnected, or it will not glow, showing that they are not. If this sounds too much like a junior-high science project, you can buy an inexpensive continuity tester anywhere you can get electric parts (even Wal-Mart). NEVER (EVER) use a continuity tester on a Live circuit or component!
