Filbyman

Hi, it sounds like the same problem I had with the S3 I bought last summer.
It has S4 door panels and I assume the same window winding mechanism.

I removed the door panel and found the back cable had an outer sleeve to help direct the inner cable towards the winding drum on the motor. The outer sleeve had become detached and when the window was going down, the cable and sleeve were going round the drum. As they went round the cable got tighter and tighter. With gravity and the tight cable, the window would not go up without assistance and the motor did as you described.

I fixed the outer sleeve back in the correct position with two plastic cable ties and have had no more problems.

Regards