With the wiring changes for solar, there are a lot of possibilities. Is the trailer new to you? Did it ever work?
First off, did you put in an inverter, or a converter? The converter takes shore power and runs your 12V
stuff and charges the batteries. An inverter runs off of the batteries and makes 120V AC so you can run some things that require AC when you don't have shore power.
There should be a battery disconnect switch that reduces current drain from the batteries when opened. I said reduces because some things are wired direct to the batteries. If the solar was installed in accordance with general recommendations there should be a disconnect switch for just the panels. In 2002, at least in my Classic 30, there was a rotary disconnect switch behind the sofa storage drawer. As wired from the factory that switch isolates the trailer loads from everything. They cannot be powered from the tow vehicle, the converter or the batteries. That said, the switch has been wired differently at times and on other trailers. On my 2001 Safari 25 when the switch was off the batteries were isolated but the converter would run the 12V
The solar system charge controller (and battery monitor if there is one) is (are) typically wired direct to the batteries. If so wired the system would charge the batteries regardless of the setting of the battery disconnect switch. But, as I said above, there should be a solar panel disconnect switch, which may be open. Lastly, originally the trailer had self-resetting circuit breakers close to the batteries. My trailer has two. If you have four, the wiring has obviously been changed so all bets are off as to how many breakers there are and where they are located.
What needs to be done is to trace all the wiring which interconnects the TV, the batteries, the DC distribution panel, the converter, the disconnect switches, the solar charge controller, and the inverter (if you have one). If you are not comfortable troubleshooting high current systems and don't have a friend who is, your best bet is to find a good RV electrician who can do it for you.