The Whirlpool residential refrigerator is not as bad as people say. If you want to install solar, you first need to determine your power requirements.
You need to calculate your appliance amp hour requirement and divide by abut 50% of your available battery amp hours. You never want to run your batteries down less than 50% assuming they are deep cycle acid batteries and not lithium. Lithium batteries are a different ballgame. Let's assume your batteries are 220 amp in parallel and series giving you 440 amp hours. 50% of that would be 220 amp hours available.
If you have the Whirlpool with an ice maker, it uses 7.2 amps on full load. We will round that down to about 5 amps per hour so in a 24 hour period it will use about 120 amp in you leave it on for 24 hours. Most people recommend turning your inverter off when you go to bed as your fridge will stay cold through the night. Based on that calculation, you would be good for about two days, which will also allow you to run LED lights sparingly. The other problem is that you have other devices that while plugged in are parasitic, which means that even if they are not on they will still pull a very small amperage. This would include any plugged in electronics even USB power cords are parasitic even if they are not charging any device.
Look at this calculator to determine what your actual requirement is: https://www.renogy.com/calculators
Now that you know your requirements, you can determine what size batteries you need and how much solar you require. I just upgraded by batteries with 4x 6v Trojan T125 giving me 240 usable amp hours. Here is the link with that info. http://www.thorforums.com/forums/f27...nger-5753.html
My next project is 4x 150W solar panels, which will sustain me for many days without running my generator for a full charge as long as I am energy smart. In all reality, everything is based on simple math and knowing what is drawing power from your batteries.
Also, not sure what year your Challenger is and how it differs from my electrical diagram but all the 5B receptacles are connected to the inverter including some other basic items like the water pump. I have attached mine as an example but I would check with Thor for yours based on your VIN. Best of luck.