I thought I needed a new drivers side switch for the drivers window, but spraying a little WD40 into the small gap where you press the switch down towards has sorted it out
It would go up fine everytime, just not always down. Water must have got in and caused it to have a bad contact
thats the same prob i had! if u take the switch apart u wil find one or 2 of the discs a funny orange colour! eventualy it wont contact atall!