yes, every RV that has at least lights inside, has a converter.
now yours may not be working correctly.
find the brand and model converter, go to the manufacturer's website, and you should be able to find a manual or a troubleshooting guide.
the converter doesn't supply power to the radio, the battery does. the converter is to recharge the battery when plugged into shore power or to convert AC power to DC power.
an inverter does the opposite, it converts 12v DC to 110v AC.
have you tested the battery?
and Zoe the Wonder Dog(R.I.P.)
'07 Roo 23SS pushing an '07 Chevy Avalanche
Equalizer WDH and Prodigy BC