Your batteries are kept charged with the built-in CONVERTER, which in turn is powered by your 110-VAC. So make sure you have 110-VAC connected to your RV and then check that your Battery is good, has water in it, and is being charged.
Your Temperature Control panel is also powered by your 12-VDC from your battery.
So, I would suspect your battery and then if it is OK, the Converter.
By the way, your Solar panel is usually there to apply a "trickle charge" to your Coach battery while it is kept in storage or is just sitting idle for a day or so, it is not designed to keep the battery charged and handle a motorhome's power load.