One place to start is easy, but then it gets really , really fussy about what we have and how to test as these steps seems so simple but are actually a real brain twister if we don't dig in and follow a straight path.
How ever we do get some really good stuff to look over.
First step if the RV is new to you, check that you are not missing some small item like brake on, etc. that can change the operation. Easy to get busy and forget some part of the routine, so double checking can avoid an afternoon of dirty work!
There is also likely to be a small switch mounted near the entry door bottom at the side. This seems to be a space that gets knocked around too much and the wires can get broken or the small reed inside the switch can get distorted and stop opening/closing when the door moves. easy to take a look there as a first stop?
Good idea to check it opens/closes if a meter is on hand! It's magnetic, so puts metal close moves the connection inside.
For fuses, you should have a panel on the outer side of the passenger seat.
Maybe look for this and check the three fuses I noted ?
View attachment 1939447
But if no good on that, it can get really tricky and the only way I can go is following the manual.
This is a manual from 2005, so possibly the correct one for your steps?
The first 7-8 pages are things to know like what series and where to find the ID info. That can seem like a drag but if you don't start with the right item, it is likely to turn into a train wreck. Best to go slow and follow the manual to get to the right section for the steps you have!
One note is that we need to make sure we get good battery to the controls as they use all kinds of electronics to tell when to move/not move!
Lots and lots of good info but it can be a trek to sort. my first tries on steps left me thinking I do NOT know enough to figure how and what it does. Certainly far more complex that I expected and not just an open/close type circuit!
But maybe you get an easy one and never have to read the whole 75 pages?
Wish you luck on that!