On the older Norcold AC/DC bay fridge/freezer units, there are (2) fuses, one for 110v and one for 12v. The unit should be taken apart on a bench, because you'll need to take the metal surround off the end. It should be
screwed in place. Watch out for residual charges on the electronics. Even
with power disconnected, you can get shocked from the capacitors in the
control circuits. When you consider the replacement cost is in the $1400.00
range, an hour or two diagnosing is definitely worth your time. Those units
are really durable, and I have seen several that have been running for 19 years (that's right!) without any problems.