Whichever pair of wires has 50v on it, (probably one of the blue pairs) goes onto the screws. Try the blue pair on the left. They look like they have been looped round the screws previously.
The other blue pair probably goes into 2 and 5 on the extension port.
The orange pairs likely don't do anything.
Edited by troublegum (Fri 02-Oct-15 21:45:12)