I would check the two reverse polarity fuses. You should have a roll of fuses and then there should be 2 by themself. Those are the reverse polarity fuses. FYI my 2009 TM the factory wired the battery + through the last fuse in the roll of load fuses, not the battery plus lug in the converter. Its strange
When looking at you converter get the model number and share it. Im think you have a wf-8945.
Also, My old TM had a gfi breaker. They look fine when they trip the gfi, but will not pass power until you reset the gfi.
In you TM blue book, in the converter owners manual, there are some aids for troubleshooting the problem you described.
here is a link to some of the wf-8945 manuals
http://wfcoelectronics.com/product-downloads/