I have the 2013 ACE 29.2 and I have the exact same wire, including color (purple) on mine and it is not plugged into anything. Mine is neatly tucked up and out of the way by the step motor. I wonder if it's used to perform diagnostics, or a bypass on the mechanism in the event of a failure or could be used for an option for the steps (altho I don't know what that could be)? Hope it helps some.
"In the game of life, I have no need for tickets on the 50-yard line, I brought my shoes, I came to play." Unknown
Don and Dale (2015 Tiffin 32 SA with 5ST, CHF, Safe-T-Plus and EEZRV TPMS) RVM106