your tv is 110v AC, not 12v DC.
you need an inverter, shore power or a generator to run the tv. same thing for all the outlets.
the other stuff you mentioned, runs on 12v DC battery power.
certain things in your RV runs on 12v battery power and some things only work when you have shore power or a generator, like the tv, air cond, outlets and so on.
didn't the dealer go over that when you did the walk-through?
and Zoe the Wonder Dog(R.I.P.)
'07 Roo 23SS pushing an '07 Chevy Avalanche
Equalizer WDH and Prodigy BC