The older Kwikee units used power window motors. When I took mine apart, I saw that there is a small, glass enclosed thermal cutoff inside the actual motor. It looks like a safety feature. So if the load is excessive (something blocking the window or short to power), the cutoff can blow and disable the motor instead of killing the windings or causing a fire.
Yes, you read correctly. You have to dismantle the motor to get at that cutoff.
If the motor is still operating with direct power to it, then it has to be a relay or switch in the controller box.
Jose