After SORN'ing (taking off the road for our US members) my XK8 convertible since the end of August 2019, I put it back on the road (with 1 months tax) to get it serviced and MOT in May this year. For the month I just undertook 90 miles but I am sure never put the roof down. I have taxed it again on 1st September with the intention to attend a Jaguar gathering on 20th and to have the leather refurbished, I took it out on 1st September and put the roof down. When I went to raise the roof, the passenger window started to come down to about half way then stopped. Using the window control on the drivers door, I was able to retract the window with no further issues. However, thinking I had a problem, I lowered and raised the roof a couple more times and each time the window would go down to about half way or would jerk down two or three times, but never fully return to the door aperture. Again, using both drivers and passenger window buttons, no issues were detected. The window goes up and down properly. I had no issues with the drivers door window. I drove the car the following day and tried the same process again. No issues. Worked perfectly for now. Has anyone had similar issues? Is it due to lack of use do you think?

 

Have you tried window reset? It looks like the controller's logic fails to find the proper place for the window.

 

Haven’t tried that yet, will give it a go.