I finally got some time this weekend to work on the RV Step. Found power was getting down to the unit some I proceeded to take the step actuator motor and gearbox apart. Once removed I applied 12v to the motor and it worked. Took the gearbox apart and found quite a bit of corrosion and dirt inside the gearbox. Cleaned, greased and reinstalled. Although this didn't seem to be the problem I serviced it anyway.
Upon re-installation I found that the step needed adjustment, seems it was opening too far and appeared to be getting jammed. So a little adjustment and I have a freshly tuned up working step..
Thanks all that replied.
Added bonus was I found a broken tailpipe hanger that was the source of a rattle so that got replaced as well.
2006 Dynamax Isata E450