If you purchased a second hand pathway, I would hook it up straight to a TV and make sure if is even working before trying to hook it in to your Greyhawk. Could have a bad Pathway. If that works, then start trying different things on your Greyhawk.
2010 Jayco Quest G2(SOLD)
2014 Jayco Eagle 33.5RETS
2007 Ram 2500 5.9L Cummins(SOLD)
2015 Ram 2500 6.7L Cummins 4WD