[jee7s]

You should find 4 wires coming out of the line/light sensor cable. If you read the data sheet inside, you'll see what each wire is for. In short, you give it supply voltage and ground on the appropriate wires (black for ground, brown? for supply), and the other two wires give you a complimentary output on NPN transistors that works with the digital I/O pins on the digital sidecar. (Don't quote me on the wire colors, check that datasheet.)

That means you should see 01 or 10 for the light and dark conditions (which is which depends on how you plug them into the sidecar, and how you write your program). If you ever see 00 or 11 you've got a fault of some sort. You should be able to do the entire hook up with 2 of the many 3 wire cables that came in the kit, a soldering iron, and some heat shrink tubing.