Using Multiplexer with an Arduino
As rzrgenesys187 said:


  If pin C0 floats HIGH and C1 is
  connected to AREF which is also HIGH,
  then there shouldn't be any change.
  Did you try connecting C1 to ground to
  get zero when you run select_wire(1)?


Yea, so it actually was switching the entire time.. however, there is a lot more distortion, so the wire connected to ground floated somewhere in the 10s. And AREF isn't high, so I don't understand how that works. AREF for me gave about the same values as ground when using

analogReference(DEFAULT);


so not sure why, but AREF is giving me near-ground values... very strange, but the MUX does infact switch, so this question is answered.. and I actually never had any problems.. meh. 

EDIT:

Actually, hooking straight into AREF does make it the input go high to 1023, so I have no idea why the input won't go that high with the MUX. maybe some kinda voltage limit, idk. I have to read up on it..

EDIT2:

Ok, finally think I'm figuring it out. Apparently breadboards leak a lot of current, so that if I was connected to C0 and it was reading C1, then a lot of voltage would leak to C1. Anyway though, connecting to AREF to C3 makes both inputs go high, so now I'm just even more confused.