Just got a z4 and noticed that the driver window only goes down and not up no matter which way I press the button. So I toke the door apart and toke the window motor off and got a new one, put the new one in and same thing happens. So I cut the wires of the window motor and reversed them and noticed now that it now only goes up and not down. Does anybody know why this is Happaning? Do I have a bad button?