There are several recent threads about the Kwikee steps and related problems, I started one myself a few months ago.
To start, download the Kwikee steps installation and troubleshooting document. Easy to read and follow.
Check the ground wires, should be 2, by removing, cleaning connections, and reinstalling.
Remove and clean the electrical connections underneath, they are exposed to all kinds of weather and dirt, and apply a small amount of dialectic grease.
Clean by scuffing up the door contacts to make sure there is a good electrical connection.
With a trouble light or multimeter, follow the troubleshooting guides to isolate what does and doesn't work.
My problem turned out to be the motor which cost around $50 and about an hour's time to replace. No special tools required.
2007 Itasca Horizon 40FD, 2015 Harley Davidson FLHTKL, 2012 Jeep Wrangler Sahara