Check under the fridge as shown in this 2005 JAYCO Designer 31RLS google photo.
This is where your 120VAC circuit breakers and 12VDC fuses are located. On the 12VDC side you see the two large REVERSE POLARITY fuses off to themself. You may also have a in-line fuse close to the battery terminals that needs checked. What causes these fuses to blow is connecting the battery terminals wrong polarity or possible sparking them when you was removing the cables etc. They can also blow these fuses if you get a shorted cell in your battery and the converter output is looking into a very large battery load trying to re-charge it. This can happen to your battery if you let it boil out fluids and not keep tabs on the fluid level in the battery.
The converter is usually under the power distribution panel in a small compartment.