I am fairly sure that is cable connects to your electric door lock which controlled by either the keyless entry or the door lock switch. It is obviously unlocked so if that is what it is for then you will not be able to lock it.
I recommend you download the wiring diagrams for your coach.
For a WKP39K:
Table of Contents
For a WKP39W:
Table of Contents
Winnebago user documentation access page:
Manuals & Diagrams
Having all the information could save you a whole lot of headaches if you or a RV Tech needs the information. It's all free so it is a good deal.
In this case, I went to the very back of that PDF and looked up the signal names (WL and WM) which told me what they were for (Power Door Lock and Power Door Unlock)
Dave