Welcome to the forum and irv2, bevans.
Does the shade have a MFG name on it and is switch in your dash or mounted separately.
In QT's # 3
you will find a section just for shades that may help you also.
All the links below in my signature have info for your Newmar
If you need a brochure and owners guide let me know.
Here is a link
for TSB's for your motor home.
Enjoy the forum and safe travels.