Paul welcome to irv2.
Here is a PDF
of step wiring that you may need. The sensors I would guess maybe the magnetic switch you will see on door frame 1/2 mounted on screen and other halve on frame. Some times they can be a plunger type also.
One thing to check is a good ground to frame of coach if its loose or dirty from road salts and like your steps will not work.
The hinge pivots on steps should be well lubed so steps do not bind possible blowing fuse. Use a KWIKEE LUBE found in RV store.
The diagram does not show a brake switch as other MFG's have so you have to make sure the switch is operated before driving off coach or damage can result if steps not retracted.
Enjoy the forums for any other problems you may have and be the knowing DAD.