now correct me if im wrong but..
It won't work the way you have it connected.
I believe that the only items you are allowed to connect to the analog ports are the pots and other analog related stuff, all other items requiring power must be hooked up into the main circuit breakers. For 5V power, what you need to do is get a 7805 voltage regulator and connect:
pin1: 12V (to fuse)
pin2: GND (to ground)
pin3: 5V (to the 5V power on encoder)
With the power connected as explained above, the encoder *should* function properly.. and really this is something for the electrical forums anyway..
