My bet would be a shorted electric element. You can unplug the leads from the control board, turn the fridge on and if the breaker doesn't pop right away, that's a good indicator of a bad element.
Make sure you replace it with the same wattage element.
2012 Copper Canyon 273FWRET being towed by a 1994 Ford F350 CC,LB,Dually diesel.
Airlift 5000 bags, Prodigy brake control, 5 gauges on the pillar.Used to tow a '97 Jayco 323RKS.
Now an RVIA registered tech. Retired from Law enforcement in 2008 after 25+ yrs.