There is a good chance it is the motor mate, I got one for £50 of Garage-D.
My window would only work intermitantly and then it refused to work full stop. The switch still clicked however, so it was either the mechanism or the motor, on Garage D's advice I got a new motor, I then unscrewed the 4 bolts as shown and removed the whole mechanism, ( the bolts are holding the motor in place).
I then took the two bolts of that hold the window in place, at the top of the picture. We then held the window to stop it droppng and took out the mechanism and motor, swapped the motor over, stuck it back into place, and then used the rubber mounts to put the window back into place.