Hi cobrabdr,
Welcome to the Heartland Owners Forum.
The factory may or may not respond, depending on who is doing what and other factors. But there are a lot of owners on the forum who may be able to help.
Does this switch hold its position when ON, or is it a momentary that's ON while you press it?
How do you know it's 120V AC?
What year and model Sundance do you have?