Auto step just stopped working

Doug, Have you autopsied any failed motors? When we had a couple older (1980's) Fords, there were continuing issues with window motors getting wet. The brushes would stick so they didn't put pressure on the commutator segments, or the segments themselves would get corroded. I could salvage those, the round motors. I don't recall needing to figure out if an armature winding had failed. Then Ford came up with the square motors, and I haven't figured out how to get the brushes back in, since they're at the other end of the motor...