Yippi, Not exactly sure what you're looking for.
If the convertor is supplying 13.3 VDC, then it has 120 VAC going to it. My best guess is that the main DC circuit breaker (30 amp, I think) from the battery (pos) is tripped. 12.4 VDC indicates a full charge on the battery itself. The main DC circuit breaker is located in the compartment by your hydraulic pump and primary battery tray. It looks like a large terminal block with a red rubber cover. The breaker reset switch is very difficult to see, but if you feel around it you will find it. I've seen pictures posted on the forum in other posts, so if you do a search, you will likely find a good picture of it. I guess I'd also double check the break-away switch, inserting (or pulling) the pin shouldn't have caused any inrush of current to trip the breaker.
By the way, the inverter should be fed from a dedicated 15 amp breaker in your AC breaker panel.
Hope this helps.