DRDIODE

I have been tasked to attach an Encoder, AndyMark No. AM-0180 to a Tough Go Mini Gear Box. I accomplished that with no problems. Had to tap the small holes to 2-56 thread. What I want to know and I have been all over the FRC papers and AndyMark technical papers is how to hook-up the Encoder to the Side Car? There are four wires connected to the US Digital E4P Encoder. 1-is for +5 Volts DC, 2-is A Channel, 3-is for GND and 4-::rtm:: is B Channel.
On the Side Car there is three pins for a Molex connector. How is the fourth wire connected? Please.

2nd DIO for Channel B. (If you need direction.)

The A and B channels go to the SIG pins of two digital inputs. You can leave the other two pins (+5 and GND) on the second input unconnected.

You hook up the +5 and GND to their respective pins and channel A and B go connect to different IO pins.
So it would look like this on the sidecar.
Sig PWR (-)
IO2 “Channel B” empty empty
IO1 “Channel A” “+5” “GND”

http://frc-labs.com/wiring-an-encoder/

In case you needed a more visual example!