I'm pretty sure the second picture in your post above is the front of the converter. I suspect the fuses are behind the front panel that must come off somehow. It does not look like an Elixir converter to me, but I think there will be two 30A fuses in there that are for protection if the battery is installed improperly. I've found they also blow if you have a high demand on the battery with the trailer plugged into shore power.
Figure out how to take the panel off and see what's behind it. It's safe to do so as long as you are NOT plugged into shore power.