Most problems I encounter with electric steps result from a lack of lubrication. If the step doesn't fall freely when you pull the clevis pin from the linkage arm, it is not lubricated properly.

Lubrication and Maintenance Schedule
NOTE: ALWAYS USE CAUTION AROUND MOVING PARTS!
Clean all mud, salt, and road grime from the step before lubricating. Lubricate all moving parts (bearings, pivot points, slides, clevis pin, and drive linkage ball) every 30 days with a good quality moisture and heat resistant penetrating grease. Kwik-Lube® spray grease is specially formulated to lubricate Kwikee® electric steps and is recommended for lubricating all moving parts. Check you owner's manual for additional information.