I have my self a new problem battery is on a regular basis getting flat I have also noticed that my left front door glass it's come's down fairly fast but to go up it's going so slowly I all ready have removed the door panel and checked if anything is holding it tight nothing there any one with some help.
i think it's just the motor getting weak. doesn't matter when it's going down but going up it's having to work really hard. try with another motor and see if it works then