Thanks to all who responded. Some of the info has helped me locate unfamiliar trailer secrets, i.e. the hidden fuse at the tongue which seems to be the main fuse controlling power from battery. Never knew it was there. In the end, a young friend, very well read mechanical and electrical genius, came over and discovered a big part of my problem was I had pushed in the battery shot off button (I had it in and out trying to solve things) and did not reset it. All 12 volt problems amazingly solved. Now I am testing and checking the slide motor connections as slide now works but for how long, as this is how this saga started. One thing we noticed is that there is a column of fuses in the converter, to the left of that column there are two fuses, one 40 the other 30 amps. I am thinking those should be the same, likely 30. Aanyhow, thanks for all your help.