If it is a motor that is bad then do a search on this forum and you find that a Ford power window motor is the same and can be purchased for about $24. Fairly easy replacement, hardest part is getting up from the ground LOL. Please do not lay under the step and keep fingers clear of the arms as the step may actuate while troubleshooting it. Follow the troubleshooting guide as previously mentioned and make sure it has a good ground. Reply with what you find out; Blessings KDK
PS what did you find out with the disconnect switch issue?