A quick an easy way to check if the motor is the problem or not, is apply external power to it. To do this get under the coach and find the 2-wire coming out of the motor to a connector, leading to the control module. Disconnect and apply 12 VDC to it.
I merely used jumper cables with one end attached to my toad’s battery and inserted two wires into the connector and attached to the other end of the jumper cables. The motor if working properly, will cycle the steps in and out.
Be careful to keep any part of your body away from the step and make sure you have proper jacks or whatever, in the event the coach lowers itself, if you have air leveling.
You will see the control module mounted adjacent to the step. It is a black plastic box with lots of wires coming out of it. This module is sometimes the culprit as it is exposed to the elements. Release the two connectors and the ground wires removed and the 3-4 screws holding the module removed, and the module will be in your hand. Make sure the ground connection is clean. I could open mine up to see the circuit board. I found it slightly damaged. Checking continuity of the soldering lines on the board, I found 2-3 damaged. You could replace the board or try adding solder to repair, which I did successfully.
There is also a fuse under the passenger armrest tied to the step switch. open up that compartment and put a small light in there Find the wires running from the back of the door switch to a black plastic inline fuse container open it up and pull out the fuse. I believe it is a 5 amp fuse.
Another common problem are the door jam magnet circuitry. I found one of my electronical connectors on the coach jam was bad. The two on the door are just magnets. The two on the coach jam have current to them that completes the circuit when the door is closed. Using my volt meter I found one was bad. Replaced it and all worked well. Bought it on Amazon. by uxcell
uxcell a14061100ux0028 3 Piece NO/NC Door Window Contact Magnetic Reed Switch Alarm Security, 0.91" Width, 13.39" Length