Hello Becker,
Assuming you have Kwikee Steps and that you have good voltage from both battery systems, go to the search box and type in "Kwikee Steps" .
Search at least a full year. There should more than one link for the #888 manual. Or you can Google, Kwikee Manual #888. I'd give you the link if I was at home but I don't have it in favorites on this computer. You don't have to disconnect your battery, first of all if you do, you can't follow the trouble shooting instructions because they are all for the electrical systems.
Sometimes when the steps are so far closed or open you won't be able to remove the clevis pin on the actuation arm at the step. My suggestion at this point is disconnect the motor leads and remove the ENTIRE motor assembly including the mounting plate. There are only four 1/4-20 nuts to remove and the entire assembly falls out. Then you can test the motor easily at your bench.
The ideas about cleaning and lubing are well founded and I would bet most failures are caused by improper preventative maintenance. I use Kwikee Lube and it works well. I relube on the road if I run into rain or dirt roads, both gum up the lube.
Good luck and let us know it come out.
PS: Check Chris Bryant's web page, he has tons of manuals just for the asking. Also 2008 is about the time US Gear bought Kwikee but if they are labeled Kwikee the give you #888 manual will give you the trouble shooting procedures. If you have a gear housing that is part of the motor, it was made by AM Machinery in Oregon, they have made sales directly to RVers at a really great price.