I imagine the problem you are experiencing has nothing to do with the problem we just found the root cause for... but wanted to share.
After i
nstalling the encoder on the transmissions with the AndyMark encoder mounting plate,
crafting two modified (PWM style three-wire)
cables to attach to the US Digital four wire cable for the encoder (2 signals from the encoder, 5V power and ground),
soldering (shrink wrapping too) the connecting wires, then
installing these
two cables (one with three wires into it, signal, power, ground; other with signal wire) to the
Digital Sidecar, then using the
LabView standard
encoder wizardry (hey, I'm a mechanical, not a SW gal) package, the encoder did not work! yikes! only a value of 1.
We spent
hours hooking up scopes, DVMs, measuring many, many things, Thank you
mentor, Bill S! Next, we called on a local
Subject Matter Expert (high five to
Laura Rhodes, of Team 100 for taking the calls and the Woodside/Carlmont team for helping on the phone during their busy day too). We were seeing strange voltage readings on the side car itself
(only the 5V LED lighted up [remember this one....], not seeing 5V on digital I/O pins using a DVM,
strange and inconsistent ground readings across the various items. We tried a different sidecar, checked so
many many things. Laura suggested we mock up a signal to the program that didn't depend on the encoders and sure enough the LabView wizard was able to read it.
FINALLY....
those pieces of data all came together (thanks to mentors Tim, Steve, and JohnG and all the students who stuck through it)....we swapped out the Wago connector from the Power Distribution panel to the Analog breakout board that we KNEW was working (battery readings, accelerometer) and used it. [i
nsert drumroll please....
].
ALL the lights now on the SideCar lit up! We didn't know there were supposed to (all this time)
AND the encoders send out readings and LIFE IS VERY VERY SPIFFY.
REMEMBER: check all the wires on the Wago connectors (Jaguars worked just fine on the Digital Sidecar which misled us into thinking all was ok w/ Sidecar and kept thinking it was the encoder wiring); and don't give up! 
Sincerely, the scribe for Team 1120, Week 5, almost 6 with only 9 days left to go!!