I wish I had an exact answer because anything is possible. However, I suspect they took power from the wrong wire and it is causing the issues. When you turn the lights on, the power circuit is open, preventing the windows to work. Somehow, they got power that is only available when the lights are off.
Have you contacted them to indicate there is a problem. If I was there, I would be able to check and diagnose what happened, but not being there really makes it a difficult because I can check where they took the power supply.
Just for curiosity, when the windows are working, does it have an affect on any of the lighting on the vehicle? If you place the light switch to the parking light selection, does the same thing happen?
Let me know if you contacted them and what they told you.
Friday, October 18th, 2019 AT 6:35 PM