Denso Window Motors, Warning - Don't use with Jaguars !

[JDNovak]

The first problem you are dealing with is a mechanical one. The window motor interface to the gearbox pinion has an anti-backdrive mechanism that locks the shaft. if there is intermittent back pressure on the gearbox output shaft it locks easier. This was probably to keep someone from prying the window down because the worm gear pitch isn't steep enough to negate backdrive.

If you are driving a load and the load doesn't keep up with the motor, it sets the mechanism and locks. if nothing detects the lockup and stops the output within a few seconds the motor protection takes over and you're done until it cools down. If you remove the output soon enough and then drive in the same direction again, the mechanism will unlock assuming the load will move. Driving in the opposite direction does not unlock the mechanism unless the load relieves on it's own.

I believe the theory that the motor shaft vibration caused by the Victors at 120hz aids in unlocking the mechanism while the Jaguars smoother output doesn't.

Just some of the frustrations of mating devices and technologies that were never designed to go together but enabling kids to keep after it until something works will hopefully pay off down the road of developing the next generation of stuff.

To test these theories, you might try driving the system into a load that is controllable (like pushing back and pulling on the steered module) and see what happens.