Search kwikee electric step troubleshooting and select ,,PDF electric steps
pg 7 has how to test the step functions without the motorhome wiring good l
after looking at the guide , it says you should have
12v from red to brown with door closed
0 v. from red to brown with door open
so the door sw is bad or the terminal connections or magnet misaligned
you could try smacking the door sw
I have a step switch that stops the door sw from working when parked if you have that sw maybe you. have it in wrong position.