I may be thinking wrong, but could the battery be shorted? If it was the line shorted somewhere from the battery to the converter, just dis-connecting the battery would not matter with a short in the line.
??? Wish I could put a meter on it.
I am confused about the part that you can still use the landing gear, if the battery was shorted, you couldn't, but if it was unhooked, the converter may have enough power to activate them. Not usually, the battery is needed in most trailers..
At Noon today, I will be working on a power problem with Driftwood Gal's Half-Time oven, Colleen and Bob are here in K.C.