It is possible to bench test a window motor for the X350 without actually plugging it into the wiring harness at the regulator. This will save tremendous time if you want to test a “used” motor or an existing motor!
The gray plugin has small numbers written on it. From the top of the plugin which has the “catch”, #1 wire is on the left;wire 4 is the last on the right (Pic). Bottom row, wire 5 on the left;wire 8 is on the right of the plugin (pic).
Pins 2 and 7 require constant 12 VDC to be applied to them. Pin 8 is your ground. Pins 4 and 3 control the motor direction (4 is down, 3 is up). Put wire 3 or 4 to the ground wire for the motor to work. Again, pins 3 and 4 require this GROUND to be applied to them to make the motor move. Do NOT apply positive to wire 3 and 4! Pin 1 is not used. Pin 6 is for the global close function (should need to ground this pin to make the motor go in the close direction).
The common fault I have had with 3 of my 4 windows on my 05 XJ8VP was the glass/motor would move only a few inches each time I pressed the switch. I had to press the switch repeatedly to get motor work/glass to move. There is an electronic board inside the motor housing that is the problem! Hopefully, someone will eventually know how to make the repair!
Hope this helps someone! I received no help in reaching out to the various forums.