My steps are old and rusting. I use PB Blaster as a lubricant. That said, I'd be more inclined to believe, due to cold weather and winter hibernation, that your batteries are a little low in charge. I'd let it warm-up a bit and put a charger on the batteries before I'd worry about some mechanical issue.
Moisture freezing could also be contributing afterall, have you ever had a power window freeze in the "up" position? Same motor in use here.
It's been a long, cold winter and mechanical components may be a little bit cranky when trying to bring them back to life.