There usually IS a fuse inside the control box at the back of the fridge. There are 2 tabs (one at either side) that can be depressed with a screwdriver to access the fuse inside. Slide the box cover toward you and you should see the fuse.
Have you checked the 12VDC that feeds into the fridge? Put a test light or voltmeter on the 2 wires going into the 2 pole white terminal, usually located about center of the fridge at floor level. The wires vary in colort, but are usually red/black , black/white or red/yellow with the first color being +12VDC . If you have 12 VDC incoming, it is either a bad fuse (hopefully) or a bad board.