Tom Benner

I have a pair that I refoamed, they worked for awhile now one of them doesn't work at all the woofer or the Tweeter. One of the wires was just shot disintegrated. What is the white rectangular piece? I can tell no discernible difference between the zero and the three switch on the back. How does the wire from the capacitor connect to the white rectangular part? Sincere, humble novice