The things to look at in the step operation. There are several things that would prevent the steps from working properly.
1. With the door open and looking into the PC there is a plunger type switch in the lower right hand corner. Check this switch to make sure the plunger moves freely and is not corroded. The contacts within the switch may be dirty. Rotating/spinning the plunger will usually clean the contacts. I have found this to be the most common cause of step problems for me.
2. The adjustable bold/nut mounted in the door that activates the plunger may need to be adjusted. It can be adjusted in or out a little to change how far the plunger is pushed in. This causes the contacts to meet at a slightly different point and might help if the contacts within the switch are worn and dirty.
Time to dive under the PC.
3. The switch from step 1 is mounted in the door frame and a large portion is outside the PC and exposed to the elements. Check for corrosion on the switch and wires.
4. The step mechanism is also exposed to the elements. Check to make sure all the pivot points move freely and nothing is binding. Lubricate if necessary. I personally use CLP (available at Wal-Mart in sporting goods department) and I stay away from WD40.
5. The last thing to check is the van battery. Make sure it is fully charged and in good operating order.
Here is a link to Kwikee Step Manual - https://www.lci1.com/assets/content/support/manuals/pg-1422279-888-Rev-OI.pdf