We recently had to replace our 38 foot Itasca Latitude (Victim to a covered storage fire). 

We picked up a used 2017 Pace Arrow 36U.  I thought I understood all the switches and buttons around the coach until.... I opened the cabinet over the microwave where the fuse panel is.  There on the left hand side is a red light switch that glows when turned on.  I have no idea what it goes to or why it’s there.  

Can someone edify me?  What is it? When should it be on?  

In an unrelated question, it’s my desire to replace some of the electrical outlets with newer ones that have USB inputs for charging new age phones and tablets without having to use bulky charger bricks.  I’ve found 15 amp and 20 amp versions.  Does anyone have experience with this as well?

Thanks in advance,

Pete

Okay, just an odd place to put an engine block preheat switch.  It’s in  an overhead cabinet  over the microwave (midcoach).  You would think a switch lwith that task would be closer to the steering wheel.  

Pete