For Electric Operation, here are some ballpark specs and ideas.
1. Resistance of 120VAC element should be around 50-Ohms
2. Current Draw of 120VAC element should be 2-3-Amps
3. You can temporarily wire a plug to the 120VAC element and power it up from an outlet.
a. Element should get HOT
b. The area the element is inserted into should get HOT
c. And the Fridge should get COLD
If you haven't done so yet, get the Service Manual. Chris's site BryantRV.com will probably offer it in the Service Documents part on the left side of his home page.
EDIT: You replaced a 5-Amp Fuse. Said fuse could be protecting 12VDC for the Logic Board (also Panel Lights). OR it could be protecting 120VAC for the Heating Element. If it blew the 120VAC fuse, better check the Element for a short before you plug it in with a non-fused test cord. Or, of course, make up your test cord with a fuse in it.
EDI-2: Be sure it isn't trying to light up LP Gas while you're testing 120VAC.
