You want to know first if the converter works. You need 120v input for sure, then see if there is any DC output.
The 9180 will have a plug-in for its 120 to a receptacle nearby. (that should be a 20a receptacle for the 20a plug on the 9180 or a 20/15)
Since there might be a problem getting generator or shore power to that receptacle, you could unplug the 9180 and plug it into a known good 120 receptacle (20/15 ok) via extension cord, with the battery bank disconnected. If there is 120v in, there should be 13.6 out.
Say that works. Now why didn't it get 120v in the rig?
A. Converter's breaker is popped (should be a 20a breaker not a 15)
B. Receptacle converter is plugged into is on a GFCI circuit that is popped
C. Generator/shore power transfer switch busted, so no 120 from Gen (but do the other 120v things work from gen just not the converter?)
Do you get 120v in the rig from shore power but not from gen?
50a rig? One of those "which leg is the converter on?" deals?