Without more detail and being able to physically see what your talking about, I won't be much help. I was under the impression from your first post that this was external lighting wiring and now your talking convertor, which is a whole different ball game. I would suggest a visit to the RV dealer of your choice or if you can find an automotive electrical specialist (not an automotive repair facility, but a place that specializes in rebuilding starters, alternator, vehicle electrical, etc.), they are sometimes less expensive on their hourly rate. Sorry I can't be any further help, but I fear that I may lead you astray and this could lead to catastrophic results for yourself and your TT if your not careful and have an advanced knowledge of ac and dc electrical systems.