There are two input connections on the breakout board: a numbered input and a +5volt next to it. As described in several sites, the "alligator" is connected to the NUmbered input, in my case, #13. The plate is connected to the adjacent 5 volt line. This is how I have wired my three homing switches, and they've been working well for years.
My assumption, therefore, is that I am simply creating a circuit that "shorts" these two lines.
Again, when I do this without making contact with the router, it behaves as it should.
I have also tried placing a 10k resistor between the numbered line and the 5volt, but it , too, does not work.
tony