The wires in these pedals are very light gauge. Since there is movement around them they can break (usually right at the connector). Anytime I open a set of pedals for any reason, I always replace those wires with heavier gauge.
Opening the pedals can be a bit of a shock if one of the springs slips off it's posts. If you study the pictures carefully, you can determine where those springs are and open that part first and assure the springs stay intact. With that, it's not that big a deal to open these things up. Also, I always squirt a big gob of hot glue around where those springs attach so I can relax while putting the thing back together.