Thanks Bill, I'll see what I can do.
I bought a new arduino and added a resistor in series with the 5V output as you suggested (still using my old code). I'm testing with just pins 2 and 3 coming from 5V and 2 led's (one on 11 = continuity, one on 12 = discontinuity.) Initially pin 12 lights up as expected, then I plug in the 2 wires coming from 5V to 2 and 3 and 11 lights up while 12 dims, all as it should. After this it's not as predictable. When I unplug pins 2 and 3 pin 11 stays lit. If I hit reset 12 lights up again and 11 dims, but now if I only plug in to pin 2 without pin 3, pin 11 lights up again.
Pins set to input will read whatever "signal" they are receiving, no? If pin 3 reads HIGH because I'm supplying voltage to it, but then I remove the supply - does it stay set as HIGH? I figured it would now read LOW.