Your information is scarce for me to help you very much but, here goes. Your Electric step runs on your motorhome's engine power, and there is usually a 12-VDC fuse panel inside the RV under the dash somewhere depending on the brand and model.
BUT, you should check a few other things;
1- the steps are activated by a magnetic switch attached to the entrance door, check that the magnet (on the door) and the switch have not been knocked loose.
2- there is a control switch for the electric step usually mounted at the entrance. (read the owner's manual on how it works.)
3- Then you should check that you have power to your step. One indicator that there is power is that the safety light under the top step is operating.