While not fun, you can pop the motor out fairly easy, or just disconnect the electrical connector going into the motor, then connect directly to a 12v battery. This can be done with a good pair of heavy duty alligator clips and leads which can be found at a good NAPA or Auto Zone. If the motor spins, it's good.
I find it is usually the controller that dies; again, not fun but relatively straight forward to replace if you are reasonably handy. Rarely do I see the reed switch in the door frame go south. And you have already eliminated the switch as a bad component. That really only leaves the motor or the controller....so check the motor and if it spins, on to a new controller!
It is also crucial that you keep the tracks clean and the gears and tracks well lubricated. This should be a monthly maintenance item. Hosing them offgood with clean water then re-lubricating with a good slide lube will go along way to keeping them happy. And they will still fail sooner than later, but hopefully with longer MTBF (mean time between failure...:-0)!
Ernie and Dianna Northern
2015 Entegra Anthem 44 DLQ2017 Entegra Cornerstone 45B
2013 Equinox toad/2014 Jeep GC diesel