check the unit out first. There really is nothing special about the microwave that is in your HTT.
however, here is one on a clearance site for
Adventure RV, it is a convection microwave. I have one in the stick frame house and we love it. I see they have a few in stock in, both SS, and black.
Also, there is a tool for checking the wiring, it is a
receptacle tester, cost about $5-8 each, seen them for much more. Well worth the investment, I have one in the house and in the HTT.