If your battery fuse is plugged in and the wires connected to the battery then it will fed the converter at all times. The solar panels will connect to the battery through a controller and will charge the batteries as needed. There is a ton of info on here about hooking up solar panels. Just search and read through the posts and I am sure you will find just what you want to do. Many posts have info on parts and pieces needed for this.
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2017 28BHBE Kitchen skylight, remote control and Aluminum wheels hitched by ProPride 3P
2017 Ram 2500 CC LB 4x4 Big Horn Cummins